WP Includes causing fatal errors

So I got a client that reported their website randomly stopped working. When i turned on debugging I got greeted with many fatal errros persisting in the WP includes folder and something with the Divi theme aswell. I tried re-uploading an updated verrson of the divi theme but it didn’t work. Can anyone recommend me some ways to recover this? There are no backups available, because client waited too long to report this issue. So no backups are present before the issue occurred.

The page I need help with: [log in to see the link]