Suddenly I saw a Failed to Load Community Plugin message when I tried to access the community menus - update or browse on my Mac.
I then found I had the same problem on my Android phone.
The verbose debug code suggested a problem with the app.json file. So I had a look into the .obsidan folder. It turned out that Dropsync ,my file sharing app on my phone to dropbox, had an issue recently and made duplicates of the core files with a suffix of app(conflict - 2021-07-19-15).json
I simply deleted all the conflicted files and voila, the problem was fixed!