The anti-cheat module that runs alongside the game to block cheats scans the system periodically. If a scan is heavy, or the heartbeat (a periodic keepalive signal) to the anti-cheat server is late, the game stutters or disconnects.
Why The anti-cheat module periodically scans game memory, running programs, and drivers → Effect The game thread stalls during the scan, or the heartbeat doesn’t go out on time → On screen Hitches at regular intervals; in bad cases, a disconnect with a security error message
At regular intervals, Right after login or maintenance, Randomly
Owner
Primary owner Game team (Client development) · Also Game team (Server development)
Game team action items
Client: run heavy scans off the game thread in small pieces, compare stutter and kick stats by anti-cheat module version (if they spike right after an update, report it to the anti-cheat vendor). Server: tolerate a heartbeat that’s late once or twice.
Ballpark numbers
A light scan usually takes under 1 ms, but a heavy scan running on the game thread can take tens to hundreds of ms at a time, depending on the implementation.
On the graph
Periodic spikes · Frame time, anti-cheat kicks
Where to look
Measure the spacing between spikes in PresentMon frame time, and tally the anti-cheat kick reasons the server received (for EOS, AuthenticationFailed / Authentication Timed Out and others in ClientActionReason) by anti-cheat module version and hardware
Confirmed if
Brief pauses repeat at a regular interval regardless of what’s happening in the game, and right after an anti-cheat update, stutter and authentication-timeout kicks rise on specific hardware
Ruled out if
Same interval on all hardware regardless of anti-cheat version: “Client garbage collection” or “Background processes taking up CPU”
Check with
Game server or client logs and metrics
Learn more
Anti-cheat modules sit deep in the OS as drivers, so they sometimes conflict with antivirus software, overlays, and other games’ anti-cheat modules. If stutter and kick reports surge on specific hardware right after an anti-cheat update, suspect this first.
Sources
Using the Anti-Cheat InterfacesEpic Games If the server doesn’t receive the client’s anti-cheat message within the set time (RegisterTimeout), it kicks the client for an authentication timeout (a client frozen by loading is a common cause); if a recent module update is the problem, roll back to the previous module