Adding a new virtual disk to a Virtual Machine fails with the error "Unable to perform this action. Contact your cloud administrator."
The Bus Type assigned to the new Hard Disk, does not match the Bust Type of the existing hard disk. Hard Disks attached to VMware Cloud Director Virtual Machines must all use the same Bus Type (SCSI Logic). This is true, even if the Hard Disks are attached toe separate virtual SCSI controllers (Buses).
Ensure the Hard Disk you are adding has the same Bus Type as the existing Hard Disk, and that the Bus Number and Unit numbers do not cross (the unit number is a subset of the Bus Number). For example, if your existing Hard Disk is using Bus 0 Unit 0, LSI Logic SAS, then your New Hard Disk should be configured to use Bus 0, Unit 1, LSI Logic SAS. See example below: