@jurinskyj: Does this still happen after restarting Zotero?
If so, would you mind uploading your database to the DB Repair Tool and posting the Upload ID here? You can ignore the download link the tool provides, but that might help us figure out what the problem is.
@dstillman: After restarting I lost the ~1600 articles I had uploaded to Zotero desktop. However, after uploading them again, the library was able to sync without error.
When Zotero restarted, the ~1600 articles I had just imported via PubMed .nbib file were gone. I imported those files again and Zotero was able to sync
Assistance would be greatly appreciated!
If so, would you mind uploading your database to the DB Repair Tool and posting the Upload ID here? You can ignore the download link the tool provides, but that might help us figure out what the problem is.