Job failed

Hi,
I am running 1 step job with run as ....... and receiving following error:

"Message
The job failed.  Unable to determine if the owner (xxxx\1234) of job test has server access (reason: Could not obtain information about Windows NT group/user 'xxxx\1234'. [SQLSTATE 42000] (Error 8198))."

I am running this with run as ..... becauase I want to take backup on file server. Any help.

Thanks