Big Bug ! App Inventor is deleting part of the code after closing and reopening the project

I discovered today that App Inventor deletes part of the saved code. Mainly this happens when I use, in some text field, the zpl code for zebra printers or when I import part of the code from the backpack.
I even tried to save the file on my desktop in .aia format but the situation didn't change and the issue it is still there. Part of the code is deleted when closing and reopening the project. The same happends also if I manualy save the project from the app invenotr menu.


Can you show some sample code that gets deleted? Which server are you working on? Is your internet connection stable. Can you show the aia that is damaged?

Hi Peter,
first of all thank you for your quick answer.

Yes I confirm that connection is good. I have Optic Fiber.

I don't know on which server am I, this is the url:

These are 2 screenshot with the deleted code "text field" containing zebra code

These are the 3 block taken from bagpack that where deleted

These is the .aia that I saved on my pc once I wrote again tha code after the deletion happened the first time.
(I saved it on my pc so that I had a full working code in case the issue was reproducing again)
joe_android.aia (139.8 KB)


P.S. It also happened again now that i just closed and opened again the page.

Are there many blocks in your backpack? What if you empty it then put the blocks in and try to get them back?

Can you also share an aia with the block with the textboxes where it is still ok?

Give mi one min, i need to write it again

I coded again and saved it

Here it is the new aia
joe_android (1).aia (140.7 KB)

I am keeping opened the progect page, if you need anything
Or if you want me to make it pubblic.

Thank you

I got this after opening the aia

Hi Peter,

exactly, that is the issue.
And also 3 blocks imported from the bagpack are missing.

This is the full code now that the project is opened in the browser.
If i Save and close the project, it gives me the issue deleting the code and the blocks.

Even doesn't show your blocks.

I studied your aia a bit. It has a number of long strings in your textboxes. Below is one of them.

^FS^CI27 ^FO202,331^GB55,0,1^FS ^FO201,332^GB0,55,1^FS ^FO201,386^GB134,0,1^FS ^FT576,0^A0R,17,18^FB387,1,4,C^FH^CI28^FDPreparato da Gruppo Caravelle srl^FS^CI27 ^FT558,0^A0R,17,18^FB387,1,4,C^FH^CI28^FDVia Appia Nuova 210 Roma - Italia^FS^CI27 ^FT292,140^A0N,17,18^FB307,1,4,C^FH^CI28^FDValori nutrizionali per ^FS^CI27 ^FT292,156^A0N,17,18^FB307,1,4,C^FH^CI28^FD100g di prodotto^FS^CI27 ^FO340,162^GFA,45,84,28,:Z64:eJz7/x8EfjDgBuz/kcA/PAoZIUoeMAAAg+kaxw==:662E ^FO340,217^GB211,0,1^FS ^FO339,247^GB212,0,1^FS ^FO339,276^GB212,0,1^FS ^FO339,303^GB212,0,1^FS ^FO339,330^GB212,0,1^FS ^FO339,358^GB212,0,1^FS ^FT342,185^A0N,17,18^FH^CI28^FDEnergia^FS^CI27 ^FT342,239^A0N,17,18^FH^CI28^FDGrassi^FS^CI27 ^FT342,269^A0N,17,18^FH^CI28^FDdi cui Acidi Saturi^FS^CI27 ^FT342,297^A0N,17,18^FH^CI28^FDCarboidrati^FS^CI27 ^FT342,323^A0N,17,18^FH^CI28^FDdi cui Zuccheri^FS^CI27 ^FT344,351^A0N,17,18^FH^CI28^FDProteine^FS^CI27 ^FT344,381^A0N,17,18^FH^CI28^FDSale^FS^CI27 ^BY1,3,40^FT386,52^BCN,,Y,N ^FH^FD>:03.03.500^FS ^FO483,165^GB0,221,1^FS ^FT497,269^A0N,17,18^FH^CI28^FD14.4g^FS^CI27 ^FT505,297^A0N,17,18^FH^CI28^FD1.2g^FS^CI27 ^FT505,323^A0N,17,18^FH^CI28^FD0.4g^FS^CI27 ^FT497,351^A0N,17,18^FH^CI28^FD29.4g^FS^CI27 ^FT497,378^A0N,17,18^FH^CI28^FD1.72g^FS^CI27 ^FT497,239^A0N,17,18^FH^CI28^FD29.2g^FS^CI27 ^PQ1,0,1,Y ^XZ

I don't know if this could cause that behavior when importing the aia or pasting blocks from the backpack.

I think I will assign one of the developers to this question.

When I put the string in a textbox I am able to copy and paste it from the backpack. Even importing the aia is working.

Hi Peter,
I was also afraid it was a matter of text field
So a workaround solution could be using "text box" instead of text field?


text box and text field are the same. :wink: App Inventors official name is "string block".

Delete first char y try again


Good eyes. :grin:

Just tested it. The character/escape code thingy is preventing the text box from being copied to the backpack.

Dear Peter,


Anyway I created text box to be sure.

Then I removed the special character from the beggin.

After that i tryed to save and close.

After reopening that, it works.
I tryed aso to export aia and re import.

It works also!!!

The character was part of the zpl label. Anyway after deleting it it is still working.

Thank you very much for your time and great support !!!

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@Juan_Antonio found the solution. Still like to know what "character" caused the problem. This is something that shouldn't happen.

ascii 197 = ┼

ascii197hereCT~~CD,~CC^~CT~ ^XA ~TA000 ~

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