App inventor error- Changes to screen 1 blocks will not be saved


I was working on a project that would check if the device is connected to the internet or not, while working on the same project, I by mistake clicked on paste all blocks from backpack and soon deleted all those blocks while app inventor still showed 2 :warning: signs:


I closed the window and opened it again but this time all of my blocks were gone and i could only see some extension blocks from my backpack while the extension wasn't loaded in that project. The blocks did not have any red border lines, when they should have. I deleted all the blocks again, wrote the same code but the next time i open the project, blocks are gone- those same 3 extension blocks were there.

Everytime I drag a block into this block section, it shows:

Same happens when I open the project.


Your project got corrupted

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Oh- So now only solution to this is starting a new project....? :sweat_smile:

Post your aia here if you wish so someone can check it.

Check_connection.aia (2.2 KB)

Unfortunately, I think it's broken beyond repair.
The Designer part seems ok, but the blocks section is way too corrupted.

ohkk.. thanks @NishyanthKumar and @dora_paz for looking into this issue :smile:

Your app uses the TaifunCamera extension:

but there is no assets folder and no sub-folder external_comps with this extension:


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So add this extension (again) to your aia using 7-Zip or WinRAR:


I can't do it for you, because this extension is paid.

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@Shobha_Singhal after doing what @Anke suggested, these are the only blocks left in your project...
you might want to restart from your latest backup...

PS: remember that is is not allowed to post projects, which include paid extensions in a public community...

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I did not add the extension so how's that possible..? :grimacing:

Did you create this project from scratch with AI2 or was it imported from another distro?

Yes- these were the only blocks in this project.. But they disappear again when opening AI2 once again.

Sorry @Taifun :disappointed:

The project doesn't contain the extension file though.. As I was working on a camera app I had many test projects so some blocks from your extension were too in the backpack..

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I created this from scratch...

But if you take these blocks from the Backpack you get an error, if the extension was not added to your app.

The extension was not there in the app, and idk how out of all the other blocks these three stay invisible and cause the error.

I also noticed that it is possible to join this extension block with other blocks when the extension wasn't added even before this happened :roll_eyes:

-Which is weird.

Try this one Check_connection.aia (2.1 KB)


Guys, I asked Shobha to put this file up, it was my intention to draw Evan's attention to it. I think her description in the first post explains a lot of things that I tested for myself but somehow a debate has veered to the left somewhat.

  1. Taifun's extension was never loaded into the Project, there was no intention to use it.

  2. When Blocks from the extension were inadvertently loaded from the Backpack, they did not show any warning (no red line borders).

  3. The extension Blocks were deleted, but either on save or on reload, the Project became corrupted and contained extension Blocks but 'lost' all the others.

It's only a test App and Shobha wrote a new one from scratch..


Yea- and Boban's project file works perfectly :grin:

Thanks @Boban !

@EWPATTON, I think it may be related to the new constants Blocks, which sometimes do not display in the Blocks area after selection.