VMware Cloud Director 10.6.x
The backup solution has stale entries in the VPX_DISABLED_METHODS table of the vCenter Server database. When a virtual machine level backup begins, the backup system informs vCenter Server to disable multiple methods for that virtual machine to ensure that the backups can complete successfully. If no backups are active for that virtual machine when this error occurs, the methods do not automatically re-enable.
Please work with 3rd party products Backup vendor to fix their code to cleanly handle enable/disable methods API.
Contact Zerto Support for assistance using the Zerto Enable Tool and the vm moref from the error to remove the stale entries from the vCenter database.
Also see KB 315486 : Storage vMotion migration fails with the error: The method is disabled by 'SYMC-INCR dd-mm-yyyy hh:mm' for more generic information about this error related to Storage vMotion.