System UI has stopped

I created an app that I never named, or made an icon choice for.  I scanned QR code and installed multiple times,  Multiple times because I couldn't find the appicon after installation.  I finally set a name, and an icon, and named it, and installed.  Now my phone(Galaxy 5) keep saying this in a notification window center screen;

Unfortunately, System UI has stopped.  

only shows an OK button, no report.  I can't get my phone to function normally at all.  I restarted, even tirned off for 5 minutes and turned on.  Same message, nothing else.  Any help please?

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It's not totally solved. I just downloaded and installed my last build. I'm having the same problem. "Unfortunately, System UI has stopped". I performed another factory reset from the boot menu. That works, but I don't know why my app is causing this malfunction.

My only guess is this.
I uploaded a bunch of Mp3s. And I couldn't download the app because it was to large. So I cut the Mp3s with an Android app. After that I could download, but that's when the problem started.

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Probably the app has problems with your disappeared mp3's. Go to the designer and delete them properly, or, replace them with short enough versions. Make sure everything works using the AI-Companion. Export an .aia file. Then try building again.
B.t.w. The app gets a name automatically, which is the same as the project name. You can change it, as you did. The same is true for the icon. If you do not provide one, you will get the friendly green Google puppet as icon.
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Thanks for trying to help.  But I think you don't understand me completely.  I delrted original mp3's , then uploaded shortened mp3's.  the app works fine in companion, but when I build for QR or download, then install on my Galaxy S5(Android version 5.1.1), That's when I get the notification window that says=  Unfortunately, System UI has stopped.

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to find out more about the Runtime Error, you can use Logcat

I normally use Eclipse and Logcat there, but if you have installed the App Inventor Software (see also http://appinventor.mit.edu/explore/ai2/setup-emulator.html), you already have everything you need to use logcat...

How to use Logcat

1. connect your device using USB with your computer

2. in File Manger go to the App Inventor directory, which is  C:\Program Files\App Inventor or similar

3. press Shift and right mouse click the subdirectory commands-for-Appinventor to get the context menu

4. select "open command window here" and you will get a command window of that subdirectory

5. enter adb logcat and the logcat will start running

To copy your log, right click, click "select all" and enter to copy the complete log into the clipboard, then open Notepad and paste it using ctrl-v.

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Thanks again everyone.  I'm so glad I asked here.  I saw one of you said "build it again"  So I just did, with the shortened .mp3's.  Everything is working great. Solved, thank you.

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