When standalone ArcGIS Server uses Windows as the Identity store, require the use of the DOMAIN\user format for logins

Workaround

Enter the login credentials in the Windows down-level logon name format.

DOMAIN\USERNAME

Windows user name formats are described in the following Microsoft article:

<a href="https://msdn.microsoft.com/en-us/library/windows/desktop/aa380525" target="_blank">https://msdn.microsoft.com/en-us/library/windows/desktop/aa380525</a>(v=vs.85).aspx

Steps to Reproduce