Extension installs fail

Extension manager is broken on my mac.
There are two errors:
Unable to update the extension id.
Missing file permission to modify extension files.
The skp2020 folder is set to 777, so the second one should not happen at all, but still does.
The other one is a riddle.
New extensions (sketchucation) also refuse to install.
Any ideas whats happening?

The Applications SketchUp 2020 folder doesn’t get written into. If you suspect file permissions you could go into this folder:

~/Library/Application Support/SketchUp 2020/SketchUp/

and rename the Plugins folder. Reopen SketchUp and make sure that a new Plugins folder was created, and it includes the four standard extensions. Then try your own extensions.

Hi Colin, Thats the weird thing: the library folder is present and 777. When I bluntly copy any plugin (from 2019 for example) into there it works, like it should. Until the extension manager, which is not working there. Stuff is listed etc, but updatebuttons refuse.

Extension Manager is one of the many things in SketchUp that is really a web view. It could be worth renaming or deleting the WebCache folder, in here:

~/Library/Application Support/SketchUp 2020/