Some believe this is directly to a Steam client update which broke EAC and was reverted. My own experience is that the error relates to the “Official Realm”. I am able to get on the “Modded Realm” with no issues BUT on the “Official Realm” the error occurs. Note: Have validated files (no errors), …

Steam - Backend Rejected The Challenge Response

Fatshark_Hedge October 8, 2021, 10:35am 2

Topic		Replies	Views
Backend reject the challenge response Technical Support acknowledged	3	1095	October 15, 2021
Fatal Error/Easy AntiCheat Error Technical Support acknowledged	13	1463	October 16, 2021
EAC Error, unable to connect to servers Technical Support acknowledged	2	1001	November 26, 2018
KNOWN ISSUE: Players Based in Russia EAC 'AUTH_ERROR' Technical Support devpost	7	96	April 14, 2025
Unknown reason deemed Untrustworthy Technical Support acknowledged	2	471	April 16, 2020