Managing preferences does not work for add ons explorer issue

I was trying to get the Field Trip Toolbox as an add on, and https://in.mathworks.com/matlabcentral/answers/60662-how-do-i-install-fieldtrip-toolbox tells me that installing it from https://www.fieldtriptoolbox.org/ doesn't go well.

I tried regenerating preferences, as stated in https://www.mathworks.com/matlabcentral/answers/99625-how-do-i-regenerate-my-matlab-preferences, but to no avail. I still get the message:

Error in matab.internal.addons.launchers.showExplorer (line 134) 
matlab.internal.addons.Explorer.getInstance.show(navigationData);

Is there no other way than to reinstall the whole package?

[Cris LaPierre]

Have you tried installing it using the Add-ons explorer?

You could also go directly to the File Exchange and download the installer there: https://www.mathworks.com/matlabcentral/fileexchange/55891-fieldtrip?s_tid=ta_fx_results

You could also try posting on the discussion forum there to get help from the toolbox author. I see someone else has already mentioned trouble installing, and they were directed here: https://www.fieldtriptoolbox.org/faq/matlab/installation/