When attempting to enable Global Permissions for a custom role created within vCenter, the operation fails with a permission denied or internal error.
VMware ESXi
VMware vCenter Server
This issue occurs because the user account logged into the vCenter Server does not possess the necessary Administrator privileges required to assign global permissions.
To successfully assign global permissions, you must use an account with full administrative rights.
cloudadmin account or the equivalent VSPHERE.local\Administrator credentials.