Hell Let Loose: Vietnam EasyAntiCheat Failed to Start (PC)

What is the Hell Let Loose: Vietnam EasyAntiCheat Error?

Hell Let Loose: Vietnam, Team17's June 2026 standalone expansion built on Unreal Engine 5.5, ships with EasyAntiCheat (EAC) as its kernel-level anti-cheat — the same enforcement layer used by Fortnite, Apex, and the original Hell Let Loose. Players are seeing two distinct launch errors: EasyAntiCheat failed to start and EasyAntiCheat: Untrusted system file (vgk.sys or similar). Both block matchmaking entirely.

The root cause for the overwhelming majority of cases on Windows 11 is EAC's enforcement of Secure Boot and TPM 2.0 — a requirement that's existed for [Battlefield 6](/en/errors/battlefield-6-anticheat-secure-boot-error) and [Valorant VAN-9001](/en/errors/valorant-van-9001-tpm-secure-boot) and has now landed on Hell Let Loose: Vietnam as of the June 2026 release. The secondary cause is the EAC installer failing to register the service because it wasn't run with administrator rights.

When does it occur?

• Immediately on clicking Play in Steam — error before the EAC splash
• After the EAC splash appears, then an EasyAntiCheat failed to start modal
• After a fresh Windows install or a switch to Windows 11
• After enabling/disabling Secure Boot in UEFI
• After a Windows 11 24H2 cumulative update reset the EAC service
• Specifically when joining Vietnam-region servers ("matchmaking failed" instead of EAC error)

Common causes

• Secure Boot disabled in motherboard UEFI (EAC requires it on Win11)
• TPM 2.0 disabled or not provisioned (fTPM on AMD, PTT on Intel)
• EAC installer ran without admin rights and failed to register EasyAntiCheat.sys
• Stale EAC install from the original Hell Let Loose conflicting with the new module
• Windows test mode / unsigned driver enforcement bypass active
• Outdated Windows 11 build (EAC requires 22H2 minimum, recommends 24H2)
• Vietnam-region servers offline or geo-routed incorrectly (matchmaking-specific)

Step-by-step fixes

1. Enable Secure Boot — reboot into UEFI (Del/F2 at POST) → Boot tab → Secure Boot → Enabled → set OS Type to Windows UEFI mode. If the option is greyed out, you may need to Clear Secure Boot Keys first, then re-enroll Platform Keys. Save and exit. Verify in Windows with msinfo32 → look for Secure Boot State: On.
2. Enable TPM 2.0 — in UEFI: AMD users enable AMD fTPM Switch (Advanced → AMD CPU fTPM), Intel users enable Intel PTT (Advanced → PCH-FW Configuration → PTT). Confirm in Windows with tpm.msc — it must show Specification Version: 2.0 and Ready for use.
3. Reinstall EAC as administrator — navigate to ...\steamapps\common\Hell Let Loose Vietnam\EasyAntiCheat\, right-click EasyAntiCheat_EOS_Setup.exe → Run as administrator → choose Hell Let Loose: Vietnam → click Repair Service. Reboot when prompted.
4. Verify EAC service is running — press Win+R → services.msc → find EasyAntiCheat_EOS → Properties → set Startup type to Manual, click Start. If it errors out, EAC was not installed correctly — repeat step 3.
5. Update Windows 11 to 24H2 or later — Settings → Windows Update → Check for updates → install all pending. EAC dropped support for 21H2 and treats 22H2 as the minimum from June 2026 onward.
6. Disable test mode and unsigned driver enforcement — open an elevated Command Prompt and run bcdedit /set testsigning off followed by bcdedit /set nointegritychecks off. Reboot. EAC refuses to load on systems with signing enforcement disabled.
7. Remove the legacy EAC install — Settings → Apps → installed apps → uninstall EasyAntiCheat (the standalone one tied to the original Hell Let Loose). Restart, then relaunch HLL: Vietnam — Steam will reinstall the EOS version cleanly.
8. For the Vietnam server matchmaking error — change matchmaking region to Southeast Asia in the in-game multiplayer menu, or set a Steam Download region close to Singapore/Tokyo. The Vietnam datacenter rolled out 48 hours after the global launch and is occasionally absent from the server list — a pattern we've documented for [Forza Horizon 6 Japan servers](/en/errors/forza-horizon-6-online-connection-error-japan-servers).

If it still doesn't work

Run dxdiag and save the output, then open Event Viewer → Windows Logs → System and filter by Source = "Service Control Manager" to confirm whether EasyAntiCheat_EOS is actually starting or being blocked by a third-party kernel driver. Common culprits are Faceit AC, Vanguard (if Valorant is installed and running), and certain ASUS Armoury Crate kernel modules — temporarily uninstall and retest.

For the underlying Secure Boot + TPM 2.0 enforcement pattern that now blankets competitive shooters, see our parallel guides on the [Battlefield 6 anti-cheat Secure Boot error](/en/errors/battlefield-6-anticheat-secure-boot-error) and [Valorant VAN-9001 TPM/Secure Boot](/en/errors/valorant-van-9001-tpm-secure-boot). If EAC still refuses to start after every step, raise a ticket at [easy.ac/en-us/support](https://www.easy.ac/en-us/support/) with your DxDiag and the EAC log at %LOCALAPPDATA%\EasyAntiCheat_EOS\Logs\.