disk I/O error

This is a generic storage I/O error — there's no way for us to tell you specifically what the problem is, but you're going to have all sorts of random, seemingly unrelated problems in Zotero until you resolve this. The most common cause is having your Zotero data directory on a network filesystem or in a cloud storage folder (where it should never be), but it could also be due to an actual physical problem with your disk or due to security software interfering with Zotero's ability to access the disk.