Failure to run command with usrun

I am trying to set up a simple rule to allow "usrun pcksh". I followed the instructions in the Admin manual on pages 247-249. However, I am getting a strange error:
$ usrun pcksh
This session is being recorded.

Failed to find remote user 'xyz\SubmitUser'


In our "xyz" vault, we do have a "SubmitUser" credential.

Looks like this error is output even if there is no rule to audit UNIX commands. The same error is displayed if I run "usrun blah":
$ usrun blah
This session is being recorded.

Failed to find remote user 'xyz\SubmitUser'


The rule:


And the "pcksh Command" from the rule:


Any ideas?