So, my first impulse, restart Fusion- which generates the message "Fusion will shut down when operations are complete" and "Uploading Files 0/11 complete". It doesn't seem to progress.
Testing the capacity to save new files, I opened and renamed an existing file. That file seems to have saved successfully. Still, I have 2 designs stuck in Grey Caution Limbo.
Every time I close Fusion a Job Status list appears showing ongoing tasks- file version uploads. If allowed to run its course, 2- no more, no less -of those uploads will complete before stalling. So, to clear this list of backlogged saved states, I have to prompt Fusion to close, wait for the two uploads, close Fusion over its protest, reload Fusion, attempt to close, rinse-and-repeat.
When the number of remaining files reduced to 3, Fusion would only process one upload before stalling; after restarting Fusion 3 times more, both of the File Not Available caution markers were removed.
I wonder then- is there an upload quota related to Cloud Credits? Here's a theory: we're credited with a certain number of uploads per session; due platform instability, I save my files frequently; credits expent, a backlog of uploads accumulated on my system- something only rectified after accumulating more session-number related upload credits.
That's the best my imagination can come up with.