Appdesigner specific file edition issue

After opening a specific .mlapp, each time I go back to the file tab inside appdesigner, I receive an dialog window : "The file has been modified outside of MATLAB Editor. Do you want to reload it?"

I have this problem only with one specific mlapp file. I have other mlapp files in the same directory for which this issue does not appear.

All these mlapp files are saved locally. They were created from guide apps, using Matlab migration tool.

This issue appears since the mlapp file creation with all the different Matlab releases I used since (R2025a on Linux now).

[Matt J]

Is it possible you still have the original GUIDE app open in the Editor?

[Cyrille]

I did the migration more than 1 year ago. I hoped this issue would be disappear with new Matlab releases.

[Matt J]

Does it still happen if you close the Editor?

[dpb]

What about any editor backup ".asv" files still hanging around that app designer might be seeing that indicate the file might still be open? Normally, they would be closed when the file is closed from the editor, but if happened to close MATLAB without, they can still be left as orphaned.

[Cyrille]

It happens each time and as long this specific .mlapp file is open

[dpb]

Weill, yes, that's what you said...but...

Did you check for .asv files while the editor is closed and you don't have the app designer open, though, left over from long ago, maybe?

If that also is not the case, I suggest opening a service ticket at <Product Support Page>.

[Cyrille]

To complete my previous reply, The issue persists even after turning off the computer. The issue is also here when I open this specific file on different PCs, even with different systems (Windows or Linux).

I also checked about the .asv files : there is no .asv file in the same directory.

I am following your advice and opening a ticket.

Thank you @Matt J and @dpb for taking the time to answer.

[dpb]

If moving the .mlapp file alone to another clean machine/install results in the same symptoms, then it definitely is something inside the file structure/content itself that is triggering the editor to think it is/has been modified outside app designer and only Mathworks internal knowledge will be able to ferret out the cause.

There are specific formats app designer uses to locate pieces-parts of the app and if one of those is slightly different in expected specific format or content, that probably is why it is triggered and why it won't go away because the specific malformed line never gets corrected as it is somewhere in the auto-generated section(s), not in the user-editable code.(*)

If it isn't too large an app and you do still have a copy of the original GUIDE implementation, might just try reconverting instead of continuing to futz with this version...

(*) You might try opening the file in the editor externally and comparing the various section headings to another .mlapp file that doesn't show the same symptoms. You might be able to find an extra linefeed or a missing comment line or somesuch that doesn't quite match the machine-generated template and be able to fix to look like the other. Make backups first before doing such, of course...

[Cyrille]

I opened a ticket and uploaded the .mlapp file. I will let you know the answer once it is resolved. I hope I won't have to redo the app migration

Answer 1

[Cyrille]

Here is the solution from Matlab helpdesk :

the solution to avoid the dialog box appearance is to check 2 options in Matlab settings :

• In "Editor/Debugger": Check the option "Reload unedited files that have been externally modified".
• In "Editor/Debugger" / "Saving" : Check the option "Save changes upon clicking away from a file."
• If these options are already enabled, try unchecking and rechecking them.

I had a secondary issue. Each time I open this specific file, 1 second after the file is open in appdesigner, a star appears next to the file name in the tab as if I did some modification in the file (I had no time to modify anything). When I want to close it, even if I did no modification since I opened it, I am asked to save the file.

The problem was due to a non standard character for the Tag property for one of the app component. I did not intend to put this character. I don't know if it was created by the GUIDE app migration or if it is a typo I did.

I changed the Tag string with standard characters to solve the issue.