After updating to Mac 8.10.8 (81008045), I'm seeing five items in a new Offline Items section in the 1Password sidebar. I can't say for certain, but I may have previously deleted at some, if not all, of these items. In other words, are these items that had been deleted but not completely purged from the database, and are now making a re-appearance? Whatever the case, like @neilmitch, I'm not able to find a way to delete them. I tried restarting my Mac, but that didn't make the offline items go away or make them deleteable. (Is there a way to rebuild the 1Password database in version 8?)