Well, what i did to fix it was to go to Basic Settings, switch to Cron, then go back to overview, let the scan run and all went fine, then went back to Basic Settings and select AJAX back, then go back to Overview and let it run and that was it, it was fixed, idk if it will work for u guys but it did for me, i think its the 2nd time this has happened to me and i fixed it like this, cause i had the .ocdata file on my Nextcloud Data folder, plus the permissions and ownership was fine as well