Why is my app not loading properly in App Designer after updating to MATLAB R2024b?

I have a complex app with several hundred GUI objects. After updating to MATLAB R2024b, my app is not loading in App Designer. I see a blank canvas (without the component library or the component browser), all the buttons except for "New" and "Open" are greyed out in the "designer" tab ribbon, and the switch to toggle between design and code view seems to be misplaced. How do I get my app to load properly?

Answer 1

[MathWorks Support Team]

This issue might be caused due to cached App Designer layout configuration files getting corrupted. The following troubleshooting steps may resolve this issue:

Workaround 1

1) Open App Designer.

2) Create a blank app and save it.

3) Use the open menu from toolstrip to open the app with the issue.

Workaround 2

1) Navigate to the directory displayed after entering the following command in the MATLAB Command Window (navigate using file explorer not MATLAB):

>> prefdir

2) Close MATLAB.

3) In the directory from step-1, delete "AppDesignerMainPanelLayout.json" and "AppDesignerMainPanelDocuments.json".

4) Launch App Designer and open the app.

Workaround 3

1) Close MATLAB.

2) Navigate back to prefdir (directory from the previous workaround).

3) Go back a step higher in the directory (e.g., the prefdir will take you to …MathWorks/MATLAB/R2024b. Go back to the “MATLAB” folder from “R2024b” in the directory).

4) Rename “R2024” to “R2024_old”. If you have multiple releases installed in your system, you will see a folder for each of the releases here. Please rename all of them with the “_old” suffix. (e.g., if you have "R2023a", rename it to "R2023a_old"). This is to regenerate prefdir when you launch MATLAB again, while also giving you the option to restore previous prefdir by removing the “_old” suffix later if needed.

5) Launch MATLAB, open App Designer and load the app