Comments

• I had a similar problem on Mac OSX, but didn't find any processes running. Deleting the Zotero data directory and then re-synching solved it for me. I think this happened because of a system crash while Zotero was running -- hopefully it doesn…

  in Mac Solution "A copy of Zotero is already open. Only one copy of Zotero can be open at a time" err Comment by oneillkza June 13, 2016