After attempting to resize the WinBackups virtual disk the Provisioning tab contains Error Message ID AP0019 "Failed to delete Volume Pool_1 because data exists on it."
This error is caused by trying to resize or deleting and recreating the WinBackups virtual disk. Once created, the WinBackups virtual disk cannot be resized as the WinBackups and RASRdisk virtuals disks are created and then the Repository and Virtual Standby virtual disks are created on top of them.
Volume Pool_1 is the operating system virtual disk and cannot be deleted.
Once this error occurs there is no way to correct the issue. A factory reset is required.