From the debug log:
Error executing backend call. |
com.vmware.vcloud.api.presentation.entity.security.OperationDeniedException: This operation is denied.
I did a quick search on that error and it may be related to an issue in vCloud Director 5.1.0 that was fixed in vCloud 5.1.1. What version of vCloud Director are you on?
Alternatively, do you have VM Storage Profiles enabled on the cluster (assuming you're using Storage Profiles)? From the vSphere Client > Management > VM Storage Profiles > Enable VM Storage Profiles. Under VM Storage Profile Status it should say 'Enabled'.