Compatibility Report

• Name of the game with compatibility issues: Mistfall Hunter
• Steam AppID of the game: 3282300

System Information

• GPU: NVIDIA GeForce RTX 4080
• Video driver version: 610.43.03
• Kernel version: 7.1.5-1-cachyos
• Proton version: experimental-bleeding-edge-11.0-407843-20260801-pb16a08-w55b819-d19dd2b-v651f17

Full system information:

Computer Information:
Manufacturer: Gigabyte Technology Co., Ltd.
Model: X670 GAMING X AX
Form Factor: Desktop
No Touch Input Detected

Processor Information:
CPU Vendor: AuthenticAMD
CPU Brand: AMD Ryzen 9 7950X 16-Core Processor
CPU Family: 0x19
CPU Model: 0x61
CPU Stepping: 0x2
CPU Type: 0x0
Speed: 6074 MHz
32 logical processors
16 physical processors
Hyper-threading: Supported
FCMOV: Supported
SSE2: Supported
SSE3: Supported
SSSE3: Supported
SSE4a: Supported
SSE41: Supported
SSE42: Supported
AES: Supported
AVX: Supported
AVX2: Supported
AVX512F: Supported
AVX512PF: Unsupported
AVX512ER: Unsupported
AVX512CD: Supported
AVX512VNNI: Supported
SHA: Supported
CMPXCHG16B: Supported
LAHF/SAHF: Supported
PrefetchW: Unsupported
BMI1: Supported
BMI2: Supported
F16C: Supported
FMA: Supported

Operating System:
CachyOS (64 bit)
Kernel Name: Linux
Kernel Version: 7.1.5-1-cachyos
X Server Vendor: The X.Org Foundation
X Server Release: 12401013
X Window Manager: KWin
Steam Runtime Version: steam-runtime_1.0.20260714.251828

Client Information:
Version: 1785347151

Video Card:
Driver: NVIDIA Corporation NVIDIA GeForce RTX 4080/PCIe/SSE2
Driver Version: 4.6.0 NVIDIA 610.43.03
OpenGL Version: 4.6
Desktop Color Depth: 24 bits per pixel
Monitor Refresh Rate: 175 Hz
VendorID: 0x10de
DeviceID: 0x2704
Number of Monitors: 1
Number of Logical Video Cards: 1
Primary Display Resolution: 3440 x 1440
Desktop Resolution: 3440 x 1440
Primary Display Size: 31.89" x 13.78" (34.72" diag)
Primary VRAM: 16376 MB

Memory:
RAM: 31687 Mb

I confirm:

• [x] that I haven't found an existing compatibility report for this game.
• [x] that I have checked whether there are updates for my system available.

Symptoms

Game launches and runs for approximately 90–120 seconds, then crashes.

Primary failure sequence:

1. Multiple D3D12 compute pipeline creation failures:
   err:vkd3d-proton:d3d12_device_validate_shader_meta: Required WaveSize range [64, 64], but supported range is [32, 32].
   warn:vkd3d-proton:d3d12_pipeline_state_init_compute: Failed to create Vulkan compute pipeline, hr 0x80070057
   LogD3D12RHI: Error: Failed to create pipeline state with combined hash ..., error 80070057
   text2. Shortly afterwards the device is lost:
   err:vkd3d-proton:vkd3d_wait_for_gpu_timeline_semaphore: Failed to wait for Vulkan timeline semaphore, vr -4.
   warn:vkd3d-proton:d3d12_device_mark_as_removed: Device ... is lost (reason 0x887a0005, "VK_ERROR_DEVICE_LOST")
   text3. Cascade of access violations (Exception 0xc0000005) → process exits.

Additional recurring issue (caught by exception handler, not immediately fatal):

• EXCEPTION_ILLEGAL_INSTRUCTION (0xc000001d) every ~20 seconds in
  MistfallHunter\Binaries\Win64\GSDK_I18N\Steam\gp.dll

Game is Unreal Engine 5, forced to D3D12 (SM6), uses EOS.

This is the probably WaveSize 64 vs 32 mismatch that has been seen in several other UE5 titles on recent NVIDIA drivers + vkd3d-proton.

Reproduction

1. Clean CachyOS install + NVIDIA 610.43.03
2. Proton Experimental bleeding-edge (2026-08-01 build)
3. Launch with PROTON_LOG=1 %command%
4. Reach main menu / start a session
5. Wait ~1.5–2 minutes → hard crash

Proton log:
(https://files.catbox.moe/iu3c6b.xz)

Might be related UE5 titles on NVIDIA:

• https://github.com/HansKristian-Work/vkd3d-proton/issues/2282 (FFXVI)
• https://github.com/HansKristian-Work/vkd3d-proton/issues/3077 (STALKER 2 on 610 drivers)