When trying to add a printer via GPO I got a warning in the application log on the remote desktop server.
The user ‘Printer1’ preference item in the ‘Printers {GUID}’ Group Policy object did not apply because it failed with error code ‘0x80070005 Access is denied.’ This error was suppressed.
Solution:
Activate “Run in logged-on user’s security context (user policy option)” under common tab on the printer properties in the GPO.