I use Zotero on my office computer and home computer, and these libraries are synched through my online Zotero library. I was cleaning up my library at home yesterday, and noticed that all subcollections were missing from one of my collections that I haven't used for awhile (this collection is called Guest Lectures, and I haven't given any of these for about 1.5 years). Is there any way to recover these subcollections? The subcolIections are also missing from my online library, and I don't have access to my office computer these days to check that. There were probably something like 5-10 of these missing subcollections. I'm pretty sure I didn't delete them accidentally, nor do I know how long they've been missing.
We don't have any access to deleted data. If you have automated historical backups of your Zotero data directory (e.g., with Time Machine on a Mac), you could temporarily disable auto-sync and swap in old copies of zotero.sqlite to try to figure out when the collections disappeared.
In your online library, going back 1.5 years, there are three instances of multiple collections being deleted at a time: five collections last September, six last June, and six in December 2018.
We don't have any reason to think there's any issue with data being deleted other than manually by accident (e.g., having the collections pane focused instead of the items pane when pressing Delete and quickly accepting the confirmation dialog). Sometimes collections do accidentally get moved elsewhere in the library, so if the items that were in those collections are still in your library, you should select one of those and view the collections containing it to see if the collection is just hiding somewhere else.
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Thanks for any help you can provide..
In your online library, going back 1.5 years, there are three instances of multiple collections being deleted at a time: five collections last September, six last June, and six in December 2018.
We don't have any reason to think there's any issue with data being deleted other than manually by accident (e.g., having the collections pane focused instead of the items pane when pressing Delete and quickly accepting the confirmation dialog). Sometimes collections do accidentally get moved elsewhere in the library, so if the items that were in those collections are still in your library, you should select one of those and view the collections containing it to see if the collection is just hiding somewhere else.