To help resolve the issue, please try the following troubleshooting steps. Please note that they should be applicable to any application that is not opening from the Toolstrip, including App Designer and Add-On Explorer. Steps 1 to 3 will need to be updated correspondingly.
1. Open the application from the MATLAB Command Window. For Simulink, you can use the following command:
>> simulink
2. Open an example from the MATLAB Command Window. For Simulink, you can use the following command:
>> openExample('simulink_general/sldemo_bounceExample')
3. Open other applications such as the Add-On Explorer or the App Designer.
4. Whitelist "MATLAB.exe" from the antivirus.
5. (From MATLAB R2023a to R2024b) Try New Desktop for MATLAB. To learn more about this, please refer to the Get Started with the New Desktop for MATLAB (Beta) documentation page.
6. Try regenerating preferences. To learn more about how to do this, please refer to the "How do I regenerate my MATLAB preferences" MATLAB Answers post.
