Login to the /tpam interface and navigation to the Management > Cache Servers menu, and select Manage Cache Servers.
Click the Accounts tab, and find the revelant Account(s) in the list. Ensure that the "Assigned" and "Enabled" boxes are checked.
Next, click the Users tab, find the user to which you are looking to assign the permssion, and ensure the "Assigned" and "Enabled" boxes are checked.
If any of these were unchecked, that would be the cause of the error.
Save the changes, and then attempt to perform the batch update again.