When enabling the core module "PHP filter" (or any other module) we're getting a white screen with this error:
Fatal error: Class 'FeedsParser' not found in /var/www/vhosts/domain.com/httpdocs/sites/all/modules/feeds/plugins/FeedsCSVParser.inc on line 11
There's no way to go back to any page at all (front and back). So there's no way to restore the website through the Backup & Migrate module. The restore has to occur manually with PHPMyAdmin.
Any idea what could cause this behaviour?