For the past few weeks, sync is stopped with an error message (1573707942). The message is that a tmp file in my zotero/tmp directory cannot be deleted.
can you find the file and delete it manually? It's likely that any security software you are using may be interfering with Zotero. Try disabling the security software and sync again.
Yes, I can. Resuming syn leads within seconds to the same error message.
The only security software running is MS security. I tried, and the problem was not solved. Nothing changed recently as far as my security software is concerned.
If you provide a Debug ID for a sync attempt we might be able to provide more info, but basically the only causes for that message that we're aware of are security software, incorrect permissions or read-only flags in the Zotero data directory (which usually results from security software), or having the data directory in a non-standard location (Dropbox, a network share, etc.).
You can also try installing Zotero Standalone, having it share your existing data directory (which is the default), and trying to sync with that. If something is interfering with Firefox's ability to write to the disk, Standalone might still work, and that might at least help narrow down the cause.
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The only security software running is MS security. I tried, and the problem was not solved. Nothing changed recently as far as my security software is concerned.
You can also try installing Zotero Standalone, having it share your existing data directory (which is the default), and trying to sync with that. If something is interfering with Firefox's ability to write to the disk, Standalone might still work, and that might at least help narrow down the cause.