Cannot start desktop MATLAB COM server when MATLAB is registered using comserver function

In MATLAB R2020a, why am I unable to start MATLAB COM server in desktop mode via actxserver or Excel Spreadsheet Link.

Running the command:

>> actxserver('matlab.desktop.application');

results in MATLAB opening in a non-desktop mode with the following warning message:

Warning: Unrecognized command line option: Desktop

In Excel, clicking the Spreadsheet Link dropdown (MATLAB icon), and launching MATLAB yields the same result.

How can I open MATLAB R2020a as a COM Server in desktop mode?

Answer 1

[MathWorks Support Team]

You are seeing this issue as a result of a bug in R2020a (updates 3 and earlier) with the "comserver" command. You can find the external bug report along which includes the workaround here:

https://www.mathworks.com/support/bugreports/2250948

As mentioned in the bug report, you can either upgrade to MATLAB R2020a Update 4 (or later) which has the fix for this issue, or you can try the following workaround:

In a R2020a MATLAB with admin rights: 

%clear registry entries
comserver('unregister','User','all')
comserver('unregister');

%register MATLAB
regmatlabserver

Please note that these commands require administrative permissions.

If you do not have administrative permissions, I would recommend reaching out to your IT department so that they can provide the necessary permissions, or try the other option of upgrading to MATLAB R2020a update 4 or later.