Problems with merging duplicate items

CKAN

We have experienced a lot of Zotero users at our University, where they don't get the option to merge duplicates (on windows computers). If they download Zotero again and upgrade Zotero it works for a couple of items, and then the merge options disappears again - and they have to download Zotero again for it to work. Is the Duplicates items unstable or is there something each user can do to make it work (and not just a couple of items at the time). We have tried updating and restarting the computer and program, and it's still really random if and when it works.

adamsmith

We've never heard of issues with merge duplicates and it should be quite stable. So my first guess would actually be that this is some sort of misunderstanding.
Where are they trying to merge exactly?

Note that merge is only available for top level items of the same item type. It's also (ovbiously I guess) only available if you have edit rights in the (group) library an item is in.

If you're positive that you've checked on those things, we'd want a screenshot of the right-click menu of two selected top level items of the same item type (upload to any free image hosting site like Dropbox, imgur.com, etc.) together with a debug ID for selecting those items and right-clicking.
https://www.zotero.org/support/debug_output