Is it possible to recover a corrupted *.mlapp file?

I was working on an app and had just got the thing to work when the file became corrupted. When I tried to run the file (and now when I try to open it), I get an error dialog:

"Error loading 'PlotDigitizer.mlapp'.

And then this appears in the command window:

"Error using which

C:\Work\Matlab\Apps\Plot Digitizer\PlotDigitizer.mlapp: Can't open file.

Error in run (line 55)

pathscript = evalin('caller', strcat('which(''', script, ''')'));"

I tried to find a solution to this online and came up with reseting preferences... which didn't work.

This the second time this has occured, forcing me to loose several hours of work, and I am not even sure what I did to cause it, if anything. It seemingly worked one minute and then not the next.

Is App Designer that unstable? Is there a way to recover this or at least copy the text portion of the code?

Also, what options do I have for backup or autosave?

[Matt J]

If you restart Matlab, is the result any different?

[Matt Brown]

Negative. Reseting the preferences required a restart of Matlab.

I attached the *.mlapp file to the original post if you want to give it a shot.

Answer 1

[Robert Philbrick]

The app became corrupt due to an invalid character entered on line 413:

if(c == <escape character here>)                        % Exit when Esc key is pressed

The "escape" character that you used is not supported in the MLAPP code file. This is a bug and I have reported it to the App Designer team.

I fixed the app (attached) so that it will now load by removing the escape character and replacing it with 'escape'. A better way to detect if the user has pressed the escape key is to add a KeyPressFcn to your app's UIFigure and use the event.Key in the callback to determine if escape was pressed:

function UIFigureKeyPress(app, event)
    key = event.Key;
    % Check if key == 'escape'
end

[Matt Brown]

Thank you very much for the fix and advice!

[mshdi mahdaklm as]

can you tell me how to fix files like this?

Answer 2

[Max Scharrenbroich]

If the .mlapp is corrupted you can still recover user-defined code and other things by opening the .mlapp as an archive using 7-zip.