For at least the last 2 days, every time I open SketchUp (SU), I’m warned that an extension needs updating. So I go to the extension manager, see that it’s @Eneroth3’s Solid Tools. I click on Update - and it fails!
I have no problem opening and using both the 3D and the Extension Warehouse from within SU.
This might have started with the latest Windows auto update. I received it about 5 days ago, but didn’t use SU until yesterday. I just updated my profile with current Windows version/build information.