Error 401 Invalid Credentials on GOOGLE PLAY download but not with .apk on device

We are new to the AppInventor...so please excuse any gaps of common knowledge that there might be in asking this question.  I also already scanned the existing posts for possible solutions but the replies are not specific to our problem.

We used Taifun´s Oauth tutorial for Fusion Tables and successfully implemented an app that when transferred via .apk to an android device works!  A big shout-out to Taifun = )

However, after uploading the .apk to Google Play and then attempting to download it, the device that it was downloaded to started to receive the 401 Invalid Credentials message.

Can it be that the Oauth mehtod of authentication is not correct for use on Google Play downloads?

Do we now have to rewrite the app to use service accounts instead?

Thanks again for any help you can possibly send our way.  

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some questions

1. did you use the login free access to let all users access your fusiontable?

2. did you store all required ids (client id, client secret and refresh token) inside the app?

3. concerning that device you get the problem now, did you test the apk on that device before uploading to Google Play? 

4. after downloading from Google Play, does it work on other devices?

5. when exactly do you get that error message? on Screen1 while receiving the access token?

Can it be that the Oauth mehtod of authentication is not correct for use on Google Play downloads?

no, of course you can upload the app the Google Play

Do we now have to rewrite the app to use service accounts instead?

no

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Thank you for your time!

1.  Yes, we did​, as taken from one of your tutorials.

2. Yes, they are stored.

3. No, we have not, as we hoped it would work from google play.

4. No, we tried out 2, and it did not work.

5. The error happened at screen2, after the access token was received.

I hope we have understood your questions correctly.

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