2017년 1월 2일 월요일

Help "Select list item: Attempt to get item number 1 of a list of 0:()" quiz app

I am making a quiz app with 4 multiple choice answers and I don't manage to find where the error is in the blocks.
Everytime the app is launched, this message appears : 
"Select list item: Attempt to get item number 1 of a list of length 0: ()" .
I have tried a lot of solutions but for the moment nothing works.

Could you please help me to find a solution ?
You could find an attached file with all the blocks.

If you are asking for help, I recommend you to make it as easy for others to be able to help you ...
You probably will get more feedback then...

which means in your case post a screenshot of your relevant blocks...

To download the aia file, upload it to  App Inventor, open it, do some bug hunting for you, etc... this takes time, and most people will not do that...

Your blocks look clean and well conceived.
From reading your blocks, I don't see any obvious error, except for starting Screen1 from the game over procedure.
Closing Screen2 seems more reasonable at that point, to return to Screen1.
See the Screens section of this FAQ for alternative screen handling techniques...

Maybe you should also post a copy of Screen1's blocks too?

In the New Question procedure, you test if you still have another question to ask.
If you do, you ask the next question and increment the index.

Afterwards, you act like the game just ended, after a single question.

You are missing an ELSE branch for that IF more questions block.
Use the blue mutator to add it,
and move the gameover call into the ELSE socket.
You might still have a problem in that gameover procedure,
but this should get you thru the first 3 questions.

Thanks a lot for your help.
I have added an ELSE and moved the "gameover call" as you suggested and the error message doesn't appear anymore !!
However, all the asnwers appear at the end of the quiz and I would like each answer to appear after each question.
Do you know how is it possible to realize that ?

Take the two big green statements that set the response correct text and background color,
and move them from their current location into the response procedure.

Perfect !
But the answer to the first question appears under the second question.
Do you know if there is a way to make the answer appear under the linked question?
Thanks a lot !!

Since you did not post any blocks, I will have to guess blindly...

Did you increment the question number before or after posting the answer?

I guess that I increment the question number before posting the answer....
You could find the blocks in the attached file.

Blocks App Apothicaire.pdf

I don't see the problem.
It seems that it should work.
I see that you are using a ListYourAnswer list to store the answers. Why?
You can just reuse the local YourAnswer for each question instead unless you plan on using that list for something else later on. 


Creating a file to send via sms

I am trying to design an app that gathers data from a variety of user inputs (predominantly check boxes but also text boxes and a date picker). I would like to be able to merge this information into one file which can then be sent by the user to his/her boss using share and selecting sms.

Any help would be gratefully received.

If the text that you are gathering is short, then you can use the built-in texting component.
Maybe this tutorial can give you some ideas:

instead of storing the information into a file, use the join block to join all the information and then use the texting component to send it

I like the sound of this idea, how do I go about it?

I tried a test of what you suggested by doing the following. 

How do I ensure the correct selection from checkbox1 is inserted into the join field?

Thanks in anticipation.

Never mind, I have worked out what I was doing wrong. I just needed to insert the checkbox1.text field into the join box.


Trouble calculating into a global

Hello, I'm having trouble calculating a value into a global.
I have a formula in Excel that is giving me the right value.
When I build it in App Inventor then the result is different than the Excel value.
I think I'm doing somthing wrong but can't work it out.

Any suggestions. Thank you!

If the comma in the formula is decimal point, then your blocks look right. Do you have the correct dphi and dlam??
Try breaking it down as follows and see if you get the right answer.

temp1 = dphi*0.329
temp1 = temp1 - 37.902
temp2 = dlam * 14.667
temp2 = temp1 - temp2
temp2 = temp2 * 0.00001

Deeply nested blocks can be made easier to read if you right-click-ExternalInputs on them.
The nesting becomes more clear.


Are you sure that you are using decimal . Instead of decimal , for the values entered ?
In AI2 you can only use . Irrespective of your country settings.


cannot change label text programmatically within while loops

I coded an app that sends a bunch of text SMS to the same person (me). I implemented a sort of "wait" block to avoid the errors I initially got (perhaps) because the app was sending the sms too fast one after the other.

I want to show on a label Text the status of the send process, such as "sending SMS 1 of 5..." and so on, but my app behaves completely differently: when I tap over "YES" in the confirmation dialog, the app "freezes" with the YES button still down and colored, until I get the final Message dialog telling me that all the sms have been sent. The confirmation dialog lets me see a part of the underlying label, and I can see that it does not change at all.


How could I force the confirmation dialog box to close before starting sending sms? How could I show the various messages using the label during the process?

Finally (I don't know if it's possible with AI2), could I catch exceptions to track exactly how many sms have been really sent successfully?

Please see the attached blocks for any detail.


use a clock component, timer interval = 1000, timer enabled = false and a global variable as counter 

in the button.click event enable the clock
inside the clock.timer event increment the counter variable and send the current message
if counter = numberOfSmsToSend then disable the clock

I read the post about single-thread some days ago, and I understood why I couldn't approach the problem using timers. The 1st version of my app implemented the so-deprecated wait feature using a timer resetting a boolean flag used as a condition to exit from an infinite while loop. The app did not function at all, resulting in a real infinite loop doing nothing. That was so because, as we could read in the link you gave me, AI2 enabled the timer, but did not ackowledge its "fired" event until it would have arrived at the end of the procedure, that is never. It queues the request from the timer having fired, but would pass the control to it only after its own end.

So I moved to a different approach, as you can see looking at my blocks: I use a timer not to react to its firing event, but to check the time elapsed from an initial moment onwards. It works fine.

I tried following your advice, using a 2nd clock fire event to (re)print (every 500ms) the status label text with the contents of a global string variable set within the for loop. As I was expecting, though, it did not work: the timer fired every 500ms but, being Ai2 in single-thread mode, its fired event code did not execute until the end of the procedure containing the for loop, when it's too late. Even following your advice literally would not work, beside having a counter incremented with no relationship with the sms actually sent.

All problems remain: the confirmation dialog does not close, its "YES" button remain freezed down and the label text does not update. Why so? In Delphi :) I used to code a component.Update/Invalidate/Refresh/Update followed by a Application.ProcessMessages if changing the aspect of interface components within long loops. Could it be something similar here in Android?
it seems to be, you did not understand what I was saying
therefore I prepared a small doSomething example for you, see screenshot and attachment

As a matter of fact, I really did not understand your advice. Now I followed your approach and all went right. Thank you again.

The only thing is that I'm trying to sent very long sms (corresponding to a bit less than 10 normal ones, that is a bit less of 160+145+8*152 characters). I imagined these sendings would require some time to complete, so I coded a pause of 5 sec between each one. On a Samsung S5 (with operator A) it all goes fine, while on a Samsung S4mini and Samsung Note 3 (both with operator B) I receive a "Generic failure, message not sent" for the 2nd sms, while they send succesfully the 3rd one (I did not try sending more than 3 "long" sms). I am about to increase the duration of the pause, as I imagine it could be something related to connection speed.

By the way, as far as you know, is there a way to catch these exceptions and react consequently in AI2, for istance retrying to send the sms generating failures? If not, could it be possible converting the ai2 code into plain java and then adding some exceptions handling structure?

you can try to catch the error in the Screen.ErrorOccurred block


A Single Thread of Execution in App Inventor Screens

The development documentation provides a very good example of why certain things in the User Interface (UI) of an app happen in the way they do. In App Inventor we use Screens to lay out components to create the UI of the app.

The main idea is that all actions that affect the UI happen sequentially. Some examples of these kind of actions could be changing the text of a label, or handling users interacting with the app via a button or a text box. 

Sequential execution in App Inventor means that different blocks can never interrupt each other.

Different blocks and handlers will always be executed in sequence. Once a block starts executing, it will execute till the end, no matter if there are other blocks reacting to the one in progress, or users pressing buttons in the app. On more technical terms, we say that everything in the UI is executed in one Thread, the UI Thread, which is responsible for all updates and interaction that happen in each Screen of your app. For this to happen, we need some kind of mechanism to keep track of what needs to be done next, and when something should be done. A very simple model would be a Queue, just like the one you join at the supermarket to pay for your shopping. Tasks can be added to a Queue in the same way that people join in the queue from the end of it.

With all this in mind, let's see the example in the documentation. (From How to add a component )

This gives a simple execution model for users: An App Inventor procedure will never be interrupted by an event handler, or vice versa; nor will one event handler be interrupted by another. This is illustrated in Figure 1:” (Ellen Spertus)

The example uses two Ball components, one CollidedWith handler that should fire as soon as Ball1 collides with anything, and an extra procedure called wait, which we don't really see what it does, but we are going to suppose that it takes 20 seconds to execute (imagine that it is loading content from the internet and it takes that long). All the code, except for the collision handler, is contained within a Click handler.
When Button1 is clicked, the two balls are positioned in exactly the same place, first Ball1, and then Ball2. Positioning the second ball in the same place as Ball1 should trigger the collision handler for Ball1. Some users would expect this to happen straight away, but if you were to execute this code, you would see that the collide handler will not execute until the click block finishes, and this would take at least 20 seconds because of the call to wait.
Following the same idea as above, you can think about the UI thread as if it was a Queue to get into the cinema; on arrival, ticket buyers will position themselves at the end of the queue.
When Button1 is clicked, we add the following things to the Queue:
⦁ position Ball1
⦁ position Ball2
⦁ wait
⦁ set Label1 text to : '...End of Button1.click...'

When Ball2 is positioned, the CollideWith handler is added to the Queue, but it cannot be executed straight away because the UI thread still has some tasks to do. So, after a couple of seconds we will see a queue such as:
⦁ position Ball1 (DONE)
⦁ position Ball2 (DONE)
⦁ wait (IN PROGRESS)
⦁ set Label1 to: '… End of Button1.click ...' (TO DO)
⦁ CollidedWith (added to the queue when the collision happens)
⦁⦁ set Label1 text to: '… Ball1.CollidedWith ...' (TO DO)

So Ball2 makes the handle trigger, but that does not mean that it will be executed straight away, instead it means that it will be added to the queue in the UI thread.

In the end, Label1 will always be assigned the value '...End of Button1.click...' first, and the value '...Ball1.CollidedWith...' later.
When both blocks finish, it will always read: “...End of Button1.Click......Ball1.CollidedWith...”.

Please note that having a procedure like wait blocking the UI is a really bad idea in an app, because as we saw in the explanation above, the app will be unresponsive for those 20 seconds, and this is not a pleasant experience for the users. If your app needs to do some expensive processing, it is quite possible that this interaction will block the app for as long as it takes.

From a design and development point of view, it is also important to note that certain blocks in App Inventor were designed with the UI thread in mind, and broken down into two different stages. For instance, the Web component Get call could be considered part 1 of a call to a web resource. This call will not block the UI because it is not performed in the UI Thread. When the response from the Get call is received, then part 2 will execute, which would be the eventGotText (or GotFile, depending on how Get was configured). If you are planning on developing a new component for App Inventor, you need to take this into account.

Also related to this idea of sequential execution, a lot of users ask why their timers do not fire on time, for instance exactly every 2 seconds. Actually the timers fire at the time they are supposed to, but this only means that their handlers get added to the scheduling queue for UI updates. If at that particular moment something else is executing in the Screen, then the actions fired by the timer will have to wait for those other actions to finish, before they can be triggered. But once they get next to be executed in the Queue, they will fire one after the other, not waiting for any intervals. The waiting was already done before joining the Queue. 

This is actually something very usual in UI libraries, from Java (Swing) to Android, and even JavaScript. The browser, in which JavaScript executes, also has a single thread of execution, generally called the event loop, and it will behave in the same way as App Inventor does. Same happens if you run JavaScript on the server through something like node.js.

This is all a simplification of what really happens, and Android can create other Threads of execution that do not conflict with the UI thread to carry on with other operations. For a deeper dig in the matter, follow the link in the Android documentation to the Painless Threading article.

problem delay procedure

This example does not work correctly.
It works the same way both (see "test_blocks.png"), and (see "test_blocks_2.png" )
And works according to the logic example shown in Figure "test_blocks_2.png"

how to fix it

test_blocks.png 표시 중

test_screen.png 표시 중

test_blocks_2.png 표시 중


Receive hour from arduino

Hi, on my school project i have to receive an hour in this format : "hh:mm" for example : "16:12" 
My school project is an automated cat flap and i have to say on an app the hour when the cat left/entered in the house, so i have also to receive a letter like "E" (enter) or "L" (leave)
so how i can know with the code if i receive an hour or the information if the cat entered/left the house ?

what about sending not only the time, but also additionally the letter E or L?

you also could use a delimiter, for example a comma, which will make ist easier in App Inventor to split the information again using the split block, example:


Yeah it's a good idea but how to say to appinventor that 16:12 is the hour and E is for enter ? 

Because that is the way you send it from the Arduino, hour first, then a commo and then E or L.
You could also use the clock of your phone to record the time. How are you going to save the information?

I'm gonna save the information with TinyDB, but i just want to know how to separate the hour and the letter when i receive for example : "16:12,E"

use the split block, you can find it in the text drawer

and learn how to work with lists

A very good way to learn App Inventor is to read the free Inventor's Manual here in the AI2 free online eBook   http://www.appinventor.org/book2 ... the links are at the bottom of the Web page.  The book 'teaches' users how to program with AI2 blocks.
There is a free programming course here http://www.appinventor.org/content/CourseInABox/Intro  and the aia files for the projects in the book are here:  http://www.appinventor.org/bookFiles  
How to do a lot of basic things with App Inventor are described here:  http://www.appinventor.org/content/howDoYou/eventHandling  .

Also do the tutorials http://appinventor.mit.edu/explore/ai2/tutorials.html to learn the basics of AppInventor, then try something and follow the
 Top 5 Tips: How to learn App Inventor

You will not find a tutorial, which does exactly what you are looking for. But doing the tutorials (not only reading a little bit) help you to understand, how things are working. This is important and this is the first step to do.


Create a real time chart in MIT app inventor with data from bluetooth

Hey all. Im new to app creation and would like to ask a question.

I created an app that shows a value in numbers (coming through bluetooth by turning on a potentiometer). My question is, is it possible to create a real time line chart with these values in MIT app inventor?
I cant seem to find a create chart option in the palette.
There's a canvas you can draw on, and a lot of sample blocks to do it
if you search for "graph" using the search box at the top of this page.
But no graph primitive, sorry.

I can offer this solution 
How to generate an animated Pie Chart using the Chart.js library
you could adjust that solution to display a line chart, see also http://www.chartjs.org/

Will check it out, thanks!

check out "biorhythm" in the gallery to see how to drw axes and scale plot data. 


link in the app

I've tried everything the previous topic has and yet the link in the app still doesn't work.  Any other ideas. 

instead of starting again a new thread, please continue in your existing thread here link in app and show us what you have tried
It would really help if you provided a screenshot of your relevant blocks, so we can see what you are trying to do, and where the problem may be.
I will close this thread.


button open website

In-app purchases using ActivityStarter>OpenBrowser and Paypal button on website.
My plan is to open the browser with the activity starter and have a Paypal button on a web page on my website. I would then try and capture the ...
13. 12. 28. 작성자: appguytry2 - 작성자 2명의 게시물 2개 - 177회 조회

Re: Link to website/URL.
You can make it open in another screen. Just put the WebViewer component on Screen2 but make sure you have a way ...a button or use the Control ...
14. 4. 1. 작성자: romanka...@gmail.com - 작성자 3명의 게시물 9개 - 561회 조회

Re: please i can't find a way , tUse these ActivityStarter with the VIEW action and a DataUri to open the phone's browser to a designated web page, for example, ...
o link button to website.
15. 12. 12. 작성자: SteveJG - 작성자 2명의 게시물 2개 - 18회 조회

Re: link in app.
... "button open website". https://groups.google.com/forum/?utm_medium= email&utm_source=footer#!searchin/mitappinventortest/button$20open$20website.
16. 4. 17. 작성자: Italo - 작성자 3명의 게시물 9개 - 28회 조회

Activity starters.
And open another link for an external website. separately i have them both working on screens but i don't know how to get one button to play the ...
14. 3. 21. 작성자: ecas...@gmail.com - 작성자 3명의 게시물 5개 - 55회 조회

Re: "Share via" button and avoid repeated questions.
Second, looking at Packaging & Sharing Apps I see one option is to upload the app to a website, but the point is if it's possible to show a ...
14. 11. 2. 작성자: David Moreno - 작성자 2명의 게시물 8개 - 97회 조회

Re: Getting an information from a website and storing it into a varible.
You can see this text for yourself by diplaying the URL you gave in a browser ( Firefox or Chrome), click with your right mouse button on the page ...
15. 8. 30. 작성자: Ghica - 작성자 3명의 게시물 5개 - 36회 조회

on click: open Google calendar.
Hello. I have one app that has normal buttons. Every button has something to do, like to show another webpage etc. All i need is, to open google ...
15. 9. 28. 작성자: Tomáš Hanzel - 작성자 1명의 게시물 1개 - 11회 조회

Open PDF files from GoogleDrive.
Thanks but... I'm new here. Visit this website because this solution seems to be the best choice for people without experience in Android ...
16. 10. 7. 작성자: Ricardo Barbosa - 작성자 3명의 게시물 6개 - 32회 조회

Re: AI2 Companion it´s not working.
You'll develop apps on our website: ai2.appinventor.mit.edu. To do live testing on your Android device just install the MIT App Inventor Companion ...
15. 8. 13. 작성자: SteveJG - 작성자 2명의 게시물 12개 - 477회 조회

Click back closes app.
When i open the app i can forward through the website but i can't go back. when i click the back button it closes the app.
15. 7. 16. 작성자: fredrick jones - 작성자 2명의 게시물 2개 - 19회 조회

Errors after Installing.
When I open either version 2 or classic, I get internal error message. In Classic, it says to use debugging.
13. 12. 28. 작성자: rpen...@kc.rr.com - 작성자 2명의 게시물 2개 - 11회 조회

Need help advancing my app(auto refresh, saving data between app launches)
First let me say this website is amazing and in a couple hours after never making an app before I already made a functioning app.
14. 1. 11. 작성자: compgo...@gmail.com - 작성자 2명의 게시물 2개 - 112회 조회

Re: Last Two Screens.
Scan the QR code the website gives you using your new barcode scanner and click the "open browser" (or similar sounding) button to open a webpage ...
14. 5. 17. 작성자: Stephen Zipprich - 작성자 3명의 게시물 18개 - 85회 조회

Image Select dont work.
My app is a basic WebViewer, its go to my website mercadoauto.net in this website users register and publish products to sell, or buy products ...
15. 5. 11. 작성자: Marquim Neto - 작성자 2명의 게시물 2개 - 24회 조회

Re: Web form report: Receiving script errors upon signing int...
This happens upon signing into app inventor 2 website ... before the welcome screen ... can't select a project, so how do I get an aia file?
14. 1. 8. 작성자: netmas...@gmail.com - 작성자 5명의 게시물 7개 - 47회 조회

Re: [MIT App Inventor] Re: All the content of my projects has disappeared.
There is a button for "build" in the App Inventor website. Furthermore, if you want to create a file with the source code you can make it with the ...
14. 3. 25. 작성자: Jorge Guzmán - 작성자 4명의 게시물 6개 - 32회 조회

Re: opening google play app.
Lets say i have 2 different links in my website starting with "https://...", i need to define the app to open those links in the native browser of ...
14. 6. 1. 작성자: nir...@gmail.com - 작성자 3명의 게시물 6개 - 68회 조회

mobile display devided in two parts.
I have problem, that in the display I see a space of button and in othere part there is the website display and I tend to open the website in all ...
16. 5. 11. 작성자: Gabriela Krizovska - 작성자 2명의 게시물 2개 - 14회 조회

App to Login and Display my mobile-optimized site.
I'd like to creat an app to Log in it with my smartphone directly( something like 2 textbox and a Login button) and then display the website ...
15. 10. 20. 작성자: Nicostak - 작성자 3명의 게시물 5개 - 20회 조회

QuickColor - Color Combination Generation and Web Design.
Once you have a color scheme chosen, QuickColor lets you see what that would like on a website. It even lets you use your own websites to see ...
14. 9. 16. 작성자: Drew Jackson - 작성자 1명의 게시물 1개 - 56회 조회

Convert a Webpage to an App.
I don't want to open the website from the app, i want to make an app that when i click on a button, for example, i would click on somewhere on the ...
15. 8. 11. 작성자: Lucía Medina Gómez - 작성자 1명의 게시물 1개 - 25회 조회

link in app

How do i create i button that when you click on it ,it sends you to a website.  THanks in advance.

Please use the search box on top of this forum page to search before starting a thread. There's a lot of user who asked these common questions before and the answers are always the same.

These are the results of searching for  "button open website"

It would really help if you provided a screenshot of your relevant blocks, so we can see what you are trying to do, and where the problem may be.


Open the browser to a designated Web page

Use these ActivityStarter with the VIEW action and a DataUri  to open the phone’s browser to a designated web page, for example,

Action: android.intent.action.VIEW

DataUri: http://mit.edu

alternatively use the webviwer component
so what have you tried?


The first block i have is the one that says When button2 click do.   Inside of that is the block call WebViewer1. Go To Url url then it has the the first block you see in procedures.

If you are asking for help, I recommend you to make it as easy for others to be able to help you ...
You probably will get more feedback then...

which means in your case post a screenshot of your relevant blocks...

To download the aia file, upload it to  App Inventor, open it, do some bug hunting for you, etc... this takes time, and most people will not do that...

a correct URL must start with http:// or https:// 

OK i tried to send the file to you.

THank u so much.  I needed this for my 5th grade project. I appreciate your help so much and i can't wait to do more apps in the future.


Problem with opening project

It happened two days ago. I make my app as aia file saved to disk. (my not last copy)
Program for control arduino through bluetooth.

Today when i am trying to open it i got an error 

notes = Browser: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0 foundIn = nb147c faultData = java.lang.NumberFormatException: For input string: "10.0" projectId = -1

I had upgrade java to the newest version.
I have tryied to import file from my komputer and got same error.
A few others project app have same problems. Some opens some not.

Is it a App inventor problem , or Google cloud .
Is this mean that my project is death, and i can not get my app project back to life ??

you do NOT need Java installed on your computer

alternatively you can try using an offline App Inventor version, for example AI2U, see here for more information Overview: Different App Inventor Distributions and Versions

I have tried the others compilator and i managed to open my file in Thunkable. I can see blocs of program the screen etc.... but when i have tested compilation i got some errors  about version that my files was created in v19 . The app isn't working. When i was Testing my app  in mit app inventor everything worked perfectly. 
It looks to me that http://ai2.appinventor.mit.edu/ changed their server to old state or something like that. 
I do not know what to do . Wait or sth.....

Well, if you are using Thunkable now, you should ask them about problems with their service. This is the MIT App Inventor 2 forum.

I think that italo you didin't understand me.
1) I can not open my app created in mit app inventor 2. two days ago it works and suddenly yesterday i could not open it.
2) I have tried many methods, using my backup app etc......
3) nothing worked.
4) Tajfun sugested to use other compiler so i have tried some of them.
5) Only thumbkable opens aia file and i can see my blocks of program. But it can not compile it properly becouse of version.
6) when i was trying in mit app inventor i saw another error android.graphics.drawable cannot cast to android.graphics.drawable.LayerDrawable

So i think that something happend with mit app and as i understand this is MIT forum !!!

We will take this and discuss it with MIT Dev team and will let you know of our findings.

I normaly worked on Chrome. But when I got an error i thougt that my browser failed. So i Installed firefox.
The error first occure in the mit cloud. Two deays erlier i made a backup of file aia to my hdd.
So i though that lost of two days of programming is not so importand and i can fix it. 
When i uploadet file i got same error.
I do not use any extension just mit emulator.
I tried to open it on the other PC with same result.

I will need the your e-mail address (the one you use to login to AI2) and the project name, and I can look into it. You can send this information directly to me at j...@mit.edu.

So there is a bug. We permit people to set font sizes to floating point numbers, but then when we read a project in, we parse it as an integer.

So if people set a font size in their project, they better use an integer, or their project gets damaged. I'll file an issue.

Update: Apparently this is a new bug just introduced a few days ago. I have found the problem and will either pull the change that caused it, or fix it.

I won't be able to deal with this for about 4 hours, but expect a fix by about 11PM U.S. Eastern Time. 0300 UTC.


An internal error has ocurred. Report a bug?

Upon entering my AI project two errors appear saying "An internal error has occured. ¿Report a bug?" In both messages press 'Cancel', allowing me to enter the designer in the Screen1. Now, when I try specifically to open two different screen to Screen1, which in my case are called "Rubro_Animal" and "Seeds" respectively, I get back the same bug, apparently the error is in those two screens and not let me do anything in these screens, enter the designer or even blocks.

On the other hand, looked into it a bit in the forum and watch people who were looking into the console programmer browser to see if they appeared problems scripts, I got some errors that appear when loading those screens, it has to do with images that are not they are loaded from the repository. I do not know if something is related to the bug that occurs when opening screens, but I mention just in case.

I would greatly appreciate help from anyone who can give it to me. Thank you very much.

Here I leave the images,

ErrorBug.PNG 표시 중

ErrorConsola.PNG 표시 중

ErrorConsola2.PNG 표시 중

ErrorConsola3.PNG 표시 중

ErrorConsola4.PNG 표시 중

ErrorConsola5.PNG 표시 중

Can you also post the blocks that are relevant to this problem?
It seems that you are trying to load images that do not exist.

is this a large project? how many screens? how many components? loads of assets like images, audio, video files?
you always can try to import your latest backup and restart working from there

I am having the same problem... it started April 21st, 2016.... projects that worked before and have not been touched can't load either... all of a sudden something on ai compiler's side has changed and i think it has caused problems for people like you and  i .... i have the apks saved from these projects working perfectly on my devices yet i suddenly cannot access them in the online program properly same error message as this user ....

And thank you very  for respond to my problem Ghica.

Yes, the browser tries to load images that no longer exist, but do not know what images are. The problembegan to appear from one moment to another.

I need at least recover all blocks are events on those screens (eg, buttons, input validation data, etc.), I do not need the variables. I could not tell exactly what they are, because they are many. Although, if you can recover the screens would be much better. I take careto get what I need from them.

Hello jopaar,
Exactly! My problem started this week. For me it's crazybecause I had time to develop the application and it is very important to me. I've taken a few tips to make the most efficient application because the project had manyblocks (over 10,000), but I need to use some blocksthat are there.

Hello Taifun, a pleasure. I've read some of your posts with tips and application development ... They are excellent.

Well, answering your questions: Yes, it is a big project(at least from my perspective). Has eight screens,among all there are more than 15,000 blocks (yes, I know. I did not know your advice to optimize projects http://twodogapps.com/?page_id=686#ShrinkingAIA thanks for that) and has about ten loaded images.

Thanks for your advice, but the problem is that ALLbackups .aia I did the project (even before there wasthe problem) when I import to AI, I get the same error appears in the same two screens. I want to mention that when I exported files .aia the error did not exist. I do not understand then why now the same error when I importappears.

And thank you very much for answering my problem.

i downloaded ai2u and installed on windows but have no idea on how to use it .... there is so much other info to wade through it is frustrating ... i  just use ai2 with my phones, tablet and windows... no emulator ... so i am at a loss ...

It is as though all the blocks on one of my pages have been deleted ... even on saved projects i haven't touched at all! That can't be right.  and my project is only 3mb in size ... but with 9 screens (i had 10 before and it still worked fine)  

please be patient, see also this already mentioned thread https://groups.google.com/d/msg/mitappinventortest/gf4jZ1mHGUk/pVXLqksjBQAJ
and try tomorrow again

i downloaded ai2u and installed on windows but have no idea on how to use it ..

for questions about AI2U please ask in the AI2U forum https://groups.google.com/forum/#!forum/ai2u
you probably might find this thread https://groups.google.com/d/msg/ai2u/Bw5xzkOAewM/K1mW4YERJwAJ helpful

Thanks for being right there with me Taifun... the only thing i hope doesn't happen is that i lose the blocks on my versions that i have done a ton of work on.... will check in tomorrow ... and do you know anything about logo trademarking for android apps with ai2? My project can be released on google play at any time now but i am afraid of my logo being stolen? Is that a valid concern or can i register mail it to myself or something like that?

Thanks for helping Taifun, I was surprised by the quickanswer to my problem.

I hope you can solve the problem with the bug, perhapsthat way I can recover much of my project.

Continue that way, my best wishes to you.

Also, I seem interesting extensions developed for AI, I hope to try them.

I downloaded ai2u and installed both starter and program (thanks for the useful links Taifun) and got it all working with a little help from the support on their website. Did some work on my project and it is going just like before! Thanks a bunch and hope you get the bug out of the new changed ai2 soon and it is great to know i can always go back to something i have here saved on my computer if something goes wrong on the site ....

There is a new release out, maybe you could try again. If it still fails, I can ask one of the developers to try and rescue your project. It would require your project I'd and Google use rid.
Hello everyone! The bug finally disappears! Thank you very much for coming so quickly to provide help. I admire the dedication and prompt response on your part.
I can go to the screens that had the bug without problems. I can recover a lot of work done.
Thanks Taifun, thanks Ghica. Best wishes for you and for the whole group of AI.