When attempt is made to create a template of a vApp to a destination catalog within VMware Cloud Director, the operation fails and the system displays the Error: "The requested operation cannot be performed because the disk is attached to the virtual machine".
VMware Cloud Director 10.X
The issue occurs because a Named Disk or an independent disk is attached to the VM in the vApp.
By design, the presence of these disk types restricts structural operations—such as template creation—on the vApp and its underlying virtual machines.
To resolve this issue, first verify the disk type, if it is "Named Disk" and then apply the steps in the shared article: