Easy Anti-Cheat is blocking the game because it sees amdihk64.dll as an untrusted system file. This is typically an AMD driver/overlay component, and EAC will refuse to go online if any hooked DLL looks modified, injected, or incompatible.
Since the issue is with an anti-cheat driver and system integrity, focus on drivers and Windows security features rather than the game itself.
- Update or reinstall AMD graphics drivers
- Completely remove current AMD GPU drivers using AMD’s cleanup utility or the standard uninstall from Settings → Apps → Installed apps → AMD Software.
- Reboot.
- Install the latest WHQL AMD driver package for the GPU from the vendor.
- Reboot again and try launching Halo MCC.
- Check for blocked or incompatible drivers (Memory Integrity)
- In Windows 11, go to Start → Settings → Update & Security → Windows Security → Device Security → Core isolation details.
- If Memory Integrity is On and shows any blocked drivers related to AMD or Easy Anti-Cheat, install updated drivers first.
- If no compatible driver exists and online play is impossible otherwise, temporarily turn Memory Integrity Off and restart. Note that this reduces protection; only do this if necessary and consider turning it back on once a fixed driver is available.
- Repair system files and component store
- Remove or disable other anti-cheat or overlay tools
- Uninstall or temporarily disable other anti-cheat systems (for example, Easy Anti-Cheat from other games, BattlEye, or similar) if they install kernel drivers that might conflict.
- Close overlays and injectors (GPU overlays, recording/streaming tools, performance overlays) before starting Halo MCC.
- Check for leftover or suspicious software
- If any untrusted tools, mods, or cheat-related utilities were ever installed, fully remove them. EAC can flag even dormant or partially removed components.
- Run a full scan with Windows Security and a reputable antimalware tool to ensure no tampering with system DLLs.
- Reinstall or repair Halo MCC’s Easy Anti-Cheat
- From the game’s install folder, run the Easy Anti-Cheat setup/repair executable for Halo MCC and choose Repair.
- Then restart the PC and try again.
If, after updating AMD drivers, repairing EAC, and ensuring Memory Integrity/driver compatibility is addressed, the error persists, collect the exact Easy Anti-Cheat error text and contact the game’s or EAC’s support with that information, as it may be a newly blocked driver version.
References: