Configuration - Installation of DeviceLock agent via Group Policy Objects fails while error 1274 appears in Windows event log
Installation via Group Policy Objects fails, event log contains error 1274 'The assignment of application DeviceLock Service from policy xxxx failed' and 'Failed to apply changes to software installation settings. The installation of software deployed through Group Policy for this user has been delayed until the next logon because the changes must be applied before the user logon'.
The problem indicates that the installation policy is set into asynchronous mode.
Change the group policy processing mode to 'synchronous'. ( Check this Microsoft article for more information on group policy processing http://technet.microsoft.com/en-us/library/cc758898%28WS.10%29.aspx