Unable to backup DC in another domain

Hi,

I am facing same issue. I am taking System State backup of Windows server 2012 R2

Windows server 2012 R2 is installed on different domian & Backup Exec media server is on different domain.

Error i am getting in job :

0xe0008488 - Access is denied.

Access Denied. Cannot backup directory  and its subdirectories.

I have diabled GRT option in job selection list & my job has completed successful, but with GRT option enabled it is failing.

Now i have enabled debug & waiting for debug log.