Hi Idris,
From the description provided it is difficult to pinpoint the exact issue, but you can refer the following steps and see if it resolves the issue:
- Close the MATLAB App Designer and all other MATLAB-related applications.
- Navigate to the following path in your system: C:\Users\Username\AppData\Roaming\MathWorks\MATLAB\R2021a\ (NOTE: Replace "Username" with your Windows username and "R2021a" with your installed MATLAB version).
- Delete the ‘AppDesignerMainPanelLayout.json’ file in the folder.
- Restart MATLAB and try launching App Designer again.
Please refer the following documentation for further details about the ‘json’ file:
