(Please start new threads for new issues — the thread you posted to isn't related. I've moved this to a new thread.)

That message means what it says. You seem to somehow have your data directory set to /opt, which is totally wrong (and I'm not sure how you would've ended up that way?). Go to your Zotero profile folder, open prefs.js, and delete the dataDir and useDataDir lines. Then make sure your Zotero data directory is in ~/Zotero, and restart Zotero.