The issue has been resolved.

Update 1: a first hotfix was deployed which enables supports ability to create backups again. However, enduser functionality is not yet recovered. In case a new backup is needed, please open a ticket and a backup will be created accordingly.

Due to an faulty patch from virtualization upstream, new backups can currently not be created. We are in contact with the vendor and a fix is already completed but not yet considered stable for production. We will apply the fix ASAP once confirmation is received.