Rephrase "This item no longer exists in your database"
The error message that occurs when an item is not found in the database should be rephrased. In my workflow, a common reason for it is not that an item "no longer exists" but that it "not yet exists" — i.e. I have not yet synced.
Proposal: "This item does not exist in your local database. This may be because it was deleted, or because your database is not yet synchronized. .... etc."
Proposal: "This item does not exist in your local database. This may be because it was deleted, or because your database is not yet synchronized. .... etc."
https://www.zotero.org/trac/ticket/1853