Email:
Since WordPress 5.2 there is a built-in feature that detects when a plugin or theme causes a fatal error on your site, and notifies you with this automated email.
In this case, WordPress caught an error with one of your plugins, Defender Pro.
Website:
Won’t run unless we deactivate defender.
[attachments are only viewable by logged-in members]
Is there a new Defender update crashing our sites?