Matlab R2021a Update 5 - Windows 10 - app designer does not open.

I'll itemize my install experience

• Downloaded "matlab_R2021a_win64"
• Run elevated: "matlab_R2021a_win64" elevated
• Exited without error, but did not run setup.exe
• Run elevated: "_temp_matlab_R2021a_win64\setup.exe"
• Instalation completed without error.
• Run Matlab

At the command line, when I enter "appdesigner", nothing happens. The command prompt returns as expected. To gain a bit more information ...

• Open windows "Task Manager"
• Task manager indicates there are 5 "Java Chromium Embedded Framework (JCEF) Helper" processes running as well as "Matlab R2021a"
• Type "appdesigner" at the matlab command prompt.
• Four more "Matlab R2021a" processes s show up momentarilly and disappear after 1-2 sec. Their icons are identical to the icons for the Java processes (i.e. not the orange Matlab peaks icon).

[Ben Abbott]

I tried installing R2020b. When "appdesigner" is entered at the command prompt, I encounter the error below.

>> appdesigner
Warning: Channel is being deleted while still open. 
> In asyncio/Channel/delete (line 168)
In matlab.internal.cef.webwindow (line 153)
In matlab.internal/webwindow/createImplementation (line 295)
In matlab.internal/webwindow (line 147)
In appdesservices.internal.browser/WebWindowController/startBrowser (line 79)
In appdesservices.internal.browser/AbstractBrowserController/start (line 122)
In appdesservices.internal.peermodel/BrowserControllerFactory/launch (line 77)
In appdesigner.internal.application/AppDesignerWindowController/startBrowser (line 75)
In appdesigner.internal.application/AppDesignEnvironment/startAppDesigner (line 103)
In appdesigner (line 28) 
Error using appdesservices.internal.browser.WebWindowController/startBrowser (line 107)
Unable to start App Designer due to an internal error.

 MATLABWindow application failed to launch. Assertion violation

Error in appdesservices.internal.browser.AbstractBrowserController/start (line 122)
            obj.startBrowser(obj.StartBrowserArguments);

Error in appdesservices.internal.peermodel.BrowserControllerFactory/launch (line 77)
            browserController.start();

Error in appdesigner.internal.application.AppDesignerWindowController/startBrowser (line 75)
                obj.BrowserController = browserControllerFactory.launch(initialBrowserState);

Error in appdesigner.internal.application.AppDesignEnvironment/startAppDesigner (line 103)
                obj.AppDesignerWindowController.startBrowser(obj.BrowserControllerFactory);

Error in appdesigner (line 28)
    appDesignEnvironment.startAppDesigner();

Answer 1

[Rishav]

Hi Ben,

Please try to regenerate the MATLAB preferences directory and then try launching App Designer again as normal. Please refer to the MATLAB answer below for the steps to regenerate the MATLAB preferences directory:

https://www.mathworks.com/matlabcentral/answers/99625-how-do-i-regenerate-my-matlab-preferences