When I sync a Windows 10 computer with zotero.org the progress circle works for awhile and then becomes the exclamation point error icon. Funny thing is that I cannot find any data that did not sync. Whats up? I seem to remember having a similar problem about five years ago that was easily resolved by removing some files....
Win error 32 during operation removeEmptyDir on file E:\[…]\storage\QJ2GTN76 (The process cannot access the file because it is being used by another process.
This generally happens when you have a PDF open on this computer that was edited (e.g., annotated) elsewhere, so when Zotero tries to download the updated version it can't overwrite the file.
Close the PDF if you have it open, or restart your computer.
(And the exclamation mark is just an indicator that there was an error. You can click on it for an actual error message. Not sure what it would say in this case, but if it's not clear we can fix it.)
Upgrade Storage
Close the PDF if you have it open, or restart your computer.