***RESOLVED*** Individual duplicate items can be selected in the Duplicates collection by using control-Click (Mac—not sure what the Windows version is).

Merge Duplicates is a fantastic feature! However, it has one limitation that I think is a basic mistake and should be resolved in future versions.

Individual items in the Duplicates collection cannot be selected, without selecting the other items that are its duplicates. Selecting one necessarily selects all duplicate items. This becomes a problem when duplicate items are not of the same Type. The Merge function doesn't work when this is the case—totally understandable. To resolve unmatched-type duplicates with the Merge function, the natural response is to change the type of one of the items so it matches the others. But this is not possible, since individuals duplicate items cannot be selected in the Duplicates collection. See the screenshot below. I think the only way to resolve different-type duplicates must be to return to the main library, search for the items, and select and change item types from there. Then return to the duplicates collection and Merge them. This is obviously sub-optimal, and the simple fix would be to allow selection of individual items in the Duplicates collection. Then the item types could be changed and the Merge function could be used right away.

Happy to be wrong, though. Please let me know if I'm missing something!

https://s3.amazonaws.com/zotero.org/images/forums/u2376597/owsb94fm9d5ua3jrai49.png