STAS DC user login error logs!

Hi;

I'm having trouble with STAS dc connection.

After users sign in to windows, the captive portal page appears. They can access the internet after logging in here.

I'm getting errors that you see below in DC logs. How to solve this problem?

 

"DCOM was unable to communicate with the computer 10.0.0.253 using any of the configured protocols; requested by PID     12ac (C:\Program Files (x86)\Sophos\Sophos Transparent Authentication Suite\stas.exe)."