Windows 11 25H2 - Latest x64 executable blocked by Windows Device Guard / App Control (0x11C7) - v1.1.9.8 works

Grim Dawn Bug Reporting
1

Reference: Bug Reporting - Crate Entertainment Forum
Hi Crate,

I believe I have isolated a launch issue with the latest Steam x64 executable.

This does NOT appear to be a Steam issue or a general Windows issue.

System

Platform:
Steam

OS:
Windows 11 Home 25H2
Build 26200.8875

Windows Security:
Device Guard / Windows Defender Application Control active

Symptoms

Launching the latest public x64 version immediately fails with:

“Failed to start process for this game:
An Application Control policy has blocked this file. (0x11C7)”

Running the executable directly from:

…\Steam\steamapps\common\Grim Dawn\x64\Grim Dawn.exe

returns:

‘Grim Dawn.exe’ was blocked by your organization’s Device Guard policy.

Windows Event Viewer

Code Integrity logs report:

Event ID 3033

Event ID 3077

Message:

“Grim Dawn.exe did not meet the Enterprise signing level requirements.”

Policy GUID reported:

{0283AC0F-FFF1-49AE-ADA1-8A933130CAD6}

Troubleshooting already performed

✓ Verified Steam files

✓ Reinstalled the game

✓ No mods

✓ No injected DLLs

✓ Direct launch outside Steam also blocked

✓ Memory Integrity OFF

✓ Windows Defender only

✓ Running latest Windows updates

Important comparison tests

Valheim (64-bit Steam game)
Launches normally.

Wallpaper Engine
Launches normally.

Grim Dawn x86 Legacy
Launches normally.

Grim Dawn latest x64
Blocked by Windows Device Guard.

Critical finding

I switched Steam to the v1.1.9.8 branch.

Result:

Grim Dawn x64 launches immediately with no issues.

Switching back to the current public build:

The latest x64 executable is immediately blocked again.

SHA256

Latest public x64 (blocked)

E5904CC8F4D96CC322D11EC58EEDD504629CCED4A32A9D9146320C10A51A11D7

v1.1.9.8 x64 (works)

4605E4C8F9ACA9CE6C00F069A59E5E33B02040DDC3F0FBB6C00ACDE925F8A27B

Authenticode

Both executables report:

Status: NotSigned

So this does not appear to simply be an Authenticode signing issue.

Conclusion

Everything points to something specific about the newest x64 executable interacting with Windows Defender Application Control / Device Guard.

The evidence suggests:

  • Windows itself blocks the executable before Steam can launch it.
  • Other 64-bit Steam games launch normally.
  • Grim Dawn x86 launches normally.
  • Grim Dawn v1.1.9.8 x64 launches normally.
  • Only the newest x64 executable is rejected.

Hopefully this helps narrow down the issue. I spent several hours comparing builds and collecting logs, and I’d be happy to provide any additional information if it helps reproduce the problem.

P.S. If it helps, I can provide the Code Integrity Event Viewer logs (Event IDs 3033 and 3077), the SHA-256 hashes, and screenshots of the Device Guard error.

2

This is a Windows Defender issue, not a game issue.

1 Like
3

Stop playing Grim Dawn at work, lol.

/jk

5

Hey, I roll out of bed, throw on my slides, and walk over to my standing desk like every other respectable remote worker.

Just because a little Grim Dawn occasionally finds its way onto one of my monitors during business hours doesn’t mean I’m playing at work.

Besides, apparently Windows Defender is already doing everything it can to keep me productive.

1 Like
6

Any way to fix this? I figured it might be some new Windows update that broke it and is doing something with Windows Defender, but I can’t seem to launch the game unless I run it in SteamOS mode at startup.

Is there a specific Defender/App Control setting, exception, or log I should be looking at to figure out exactly what’s blocking the executable?

7

I assume if it’s a work pc you don’t have access to whitelist folders in Defender?