A role is created for the vRanger account to use when logging on to the vCenter server. The role is created and all the requested priviliges are granted to the role. Everything appears OK, but backup jobs fail with a 3201 error when trying to open the target VM's vmdk file.
The role's priviliges are defined at the datacenter level rather than at the vCenter level.
Select the datacenter in the vSphere client. Open the Permissions tab and remove the which the vRanger login account. Select the vCenter in the vSphere client, and open the Permissions tab. Right-click in the white space and add the account that vRanger uses for login.