App designer opening seems to kill the help window

When starting up Matlab the help window opens up fine and displays whatever is asked. But after starting 'app designer' whenever I type something in the help search window, an empty help window appears. I have to go to a webpage to search the documentation. Is this some sort of path or environment variable issue?

[Suvansh Arora]

This seems to work fine for me, could you please provide precise set of action to reproduce this issue?

This is how, I am performing the mentioned task:

• Open App designer.

>> appdesigner

• Opening help window.

>> helpwin fft

or

>> doc fft

[Michael Cole]

Thanks for you help. I open up Matlab 2022b. 'Help' works fine. I type "appdesigner" on the command line. It opens up fine. I go to the upper right icon of a question mark in the appdesigner and type "rem" for example. What opens up is the enclosed picture. I return to Matlab itself and type "rem" and now I get the empty window that previously had the interactive documentation. 'helpwin fft' opens up a little help window but not the one I got when I first started Matlab. 'doc fft' opens up another empty window.

[James]

Are there any other steps you’re leaving out? Are you opening a certain file and then the issue occurs?

[Michael Cole]

Yes, thanks for your interest. I've been working intensely with Tech Support to find what's causing this for a while now. I've discovered a few things. Upon opening Matlab everything involving 'help' and 'codeanalyzer' works fine. After starting 'appdesigner' everything is still fine. Upon opening any and every 'mlapp' file, both 'help' and 'codeanalyzer' show blank screens. In fact the previously opened 'help' window has now turned blank.

This problem happens on both my Macs but does not happen on my Windows 10 machine.

I did try a complete Matlab re-install but that didn't fix my problem.

Some commands Tech Support showed path errors. See below.

>> appdesigner

>> url = 'google.com';

>> cmd = sprintf('MATLABWindow --url=%s ', url);

>> system(cmd)

zsh:1: command not found: MATLABWindow

ans =

127

>> cd(fullfile(matlabroot,'sys','jxbrowser-chromium','maci64','chromium'))

Error using cd

Unable to change current folder to

'/Applications/MATLAB_R2022b.app/sys/jxbrowser-chromium/maci64/chromium' (Name is nonexistent

or not a folder).

>> !otool -L libjxbrowser-common64.dylib | grep -i found

error: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/otool-classic: can't open file: libjxbrowser-common64.dylib (No such file or directory)

I suspect some sort of path problem or inconsistency with XCode on my Macs.

Answer 1

[Suvansh Arora]

This can be caused for various reasons, please try below mentioned workarounds to resolve this issue:

• Sign out "MathWorks Account" in MATLAB Desktop.
• Restart MATLAB and sign in "MathWorks Account" again.

Attaching below related ML answers community questions for your reference,

• Why does my Help Browser or Web Browser display blank pages in MATLAB on my Windows system? - MATLAB Answers
• Matab Help Window is just a black screen. - MATLAB Answers

If you still face any issues, feel free to reach out to MathWorks Technical Support.

[Michael Cole]

I've been working with tech support. The solution probably is a clean install. Even Code Analyzer is blank once appdesigner is started. Thanks for your attention.

Answer 2

[Michael Cole]

After struggling with this problem for weeks, Mathworks engineers and I had a conference call where I shared my Mac desktop with them and they saw that there was a problem. They are looking into it. In the meantime they provided me with a workaround that works on both my Macs. Here it is:

cd /Applications/

cd MATLAB_R2022b.app

./bin/matlab -cefdisablegpu

This apparently disables hardware acceleration on my GPU or forces it to downscale its properties. I note this "-cefdisablegpu" issue has been used to solve several other problems users were having like this one about typing latency:

https://www.mathworks.com/support/search.html/answers/1575028-why-is-cursor-movement-and-scrolling-slower-in-the-matlab-editor-on-linux-in-r2021b.html?fq%5B%5D=asset_type_name:answer&fq%5B%5D=category:matlab/desktop-tools-and-development-environment&page=1

[James]

I don’t know much about -cefdisablegpu specifically, but it sounds like the command specifically disables GPU acceleration for CEF-related things. Basically any window that uses Chromium, from my understanding. I’m curious what the full fix’ll be.