I’m having the same problem.
I cannot access or open my files on Trimble connect from within Sketchup (Desktop)
I can use the Launch Trimble Connect option though so it must be connecting and communicating with it to some degree.
I can access my Trimble connect files via Sketchup online.
It was working fine last week.
Things to try:
- Quit or exit SketchUp and LayOut.
- In the standard browser, head for https://myprofile.trimble.com, sign out and clear the cache and cookies (press CTRL + F5 to reload
- In another tab, head for https://profile.sketchup.com and repeat (clear cache and cookies, hit CTRL +F5)
- Open SketchUp and try again.
Tried that, still doesn’t work.
I might try a system restore later today. I was using Trimble connect on Thursday without issue. Friday morning I had a few windows updates install so I guess it’s possible that something has been corrupted.
The next step would be trying to renam or delete the .tc folder in the Local App data:
%localappdata%\SketchUp\SketchUp 2025\SketchUp\
So I restored windows to last week before the updates. Nothing.
Cleared the cache. Nothing.
Ran a chkdsk. Nothing.
Rebooted the router. Nothing.
Tried repairing Sketchup. Nothing.
Unistalled. Rebooted. Re-downloaded Sketchup.
Then I could no longer log in. “Invalid Password” !?
It turns out, the IT manager had decided to reset the account password. 
And not tell anyone.
I’m now logged in and everything seems to be working fine.
Thanks for the suggestions Mike, sorry it was all a big fat waste of time.
Another possible cause to add to the troubleshooting suggestions. Asking that seems like it’s close to asking, “Is it turned on?”
Glad you got it sorted, though.