I have read multiple discussion threads by other users with this problem as well as the Documentation article on Zotero data directories, but I still can't figure out how to restore my library. Details of my circumstance are below.

1. I am using Zotero standalone for Mac 5.0.66 and do not have Zotero Firefox

2. My Data Directory location is the standard /Users/lucy/Zotero. I can find zotero.sqlite in this directory; it is 218 MB and shows that it was modified this AM. (My library contains ~2300 items).

3. I did a Terminal search for zotero.sqlite. (Zotero-old copy is a copy I made to preserve the contents of the Zotero folder, in case I wanted to try changing things in the current directory.) Here are the results:

Last login: Sun May 5 11:09:01 on console
Lucys-MacBook-Pro-2:~ lucy$ mdfind -name zotero.sqlite
/Users/lucy/Zotero/zotero.sqlite
/Users/lucy/Zotero/zotero.sqlite-journal
/Users/lucy/Zotero-old copy/zotero.sqlite.1.bak
/Users/lucy/Zotero-old copy/zotero.sqlite
/Users/lucy/Zotero-old copy/zotero.sqlite.bak
/Users/lucy/Zotero/zotero.sqlite.1.bak
/Users/lucy/Zotero-old copy/zotero.sqlite-journal
/Users/lucy/Zotero/zotero.sqlite.bak
Lucys-MacBook-Pro-2:~ lucy$

4. I tried un-installing and then re-installing Zotero standalone to no avail.

5. I can still see all my entries in my Zotero online library. Zotero standalone shows that syncing as enabled and that the standalone libraries is currently synced with my online account. (Obviously this not the case.)

6. I wonder whether the possible cause of my library's disappearance is that I am using a Dropbox folder for my Linked Attachment Base? Yesterday, on another device, I went into this folder directly and annotated some pdfs that were there without going through Zotero.

Thanks for your help with this.