"Merged items must all be of the same item type"

dpesetsky · 2026-09-06T18:45:46+00:00

I have ended up with a large number of duplicates flagged as such by Zotero that I cannot merge in the Duplicates window because "Merged items must all be of the same item type". Most of these are real duplicates that just ended up with pairs of item types like "thesis" vs. "manuscript", "journal article" vs. "conference paper" etc. But not only can't I merge them in the Duplicates window, but I can't highlight just one of the pair in that window to change its item type so I can duplicate it. I seem to have to switch to My Library or a collection, search for the item whose type is wrong and manually change it there -- for every set of duplicates. This is going to be long and crazily laborious for so many duplicates!

Or am I missing something? (I hope so.)

https://s3.amazonaws.com/zotero.org/images/forums/u4066549/1k6t4asazm9rnpieia8v.png

(I do have Zoplicate -- tried turning it off as well -- don't think there's any help there.)

adamsmith · 2026-09-06T18:53:58+00:00

You can select individual items using Ctrl+click (I thought Zoplicate allowed merging different item types, but might misremember)

dpesetsky · 2026-09-06T20:16:09+00:00

Very helpful, thank you!! Though:

1. It would be great if this was made clear in the app, for example in the plentiful space around:
https://s3.amazonaws.com/zotero.org/images/forums/u4066549/e5yj2rh4av3ugr58b590.png

2. Also, it's a bit of a mess to use. Ctrl-Clicking on one of the two highlighted parent items does nothing, in fact. You have to first highlight an individual pdf, and only then can you ctrl-click on one of the duplicates and change its item type so Merge is possible.

Still, better than not being able to do it at all. Thank you.