I am trying to run Elden Ring under Linux using an NVIDIA RTX PRO 5000 Blackwell card. The driver is NVIDIA 595.71.05 and my OS is Ubuntu 24.04 (Kernel 6.17.0-35-generic). The game repeatedly crashes during launch after getting past audio initialization.

I've tested this across multiple Proton versions:

Proton Experimental (11.0-1-20260609)

Proton 11.0 Beta 5

GE-Proton10-34

proton-cachyos-11.0-20260601-slr-x8664

My furthest progress run was using proton-cachyos-11.0-20260601-slr-x8664 combined with binary patches to bypass an XAudio2 fast-path bug (the game was incorrectly fast-pathing GetModuleHandleExA and returning a NULL handle without loading xaudio2_9.dll). I applied the JE->JMP patch to force the lazy-load path and fixed the rcx=0 lock xaddl null dereference in moSoundManager.cpp:880.

However, the game still dies because it fails to initialize the Vulkan device through VKD3D-Proton.

In my attached Proton log (using launch options: WINEDLLOVERRIDES="xaudio2_9=n,b" VKD3D_CONFIG=nonvx,nouploadhvv,descriptor_heap PROTON_LOG=1 %command%), there is a consistent block of Blackwell-specific format errors indicating missing format support in vkd3d-proton:

fixme:vkd3d-proton:d3d12_device_CheckFeatureSupport Unhandled format 0x70.
fixme:vkd3d-proton:d3d12_device_CheckFeatureSupport Unhandled format 0x71.
fixme:vkd3d-proton:d3d12_device_CheckFeatureSupport Unhandled format 0x72.
err:vkd3d-proton:vkd3d_get_format Invalid format 116.
fixme:vkd3d-proton:d3d12_device_CheckFeatureSupport Unhandled format 0x74.
err:vkd3d-proton:vkd3d_get_format Invalid format 117.
...
fixme:vkd3d-proton:d3d12_device_CheckFeatureSupport Unhandled format 0x84.

Immediately after checking these extensions and missing WMMA features, VKD3D fails with vr -3:

info:vkd3d-proton:vkd3d_instance_apply_application_workarounds Detected game eldenring.exe, adding 3 configs, removing 0 configs.
warn:vkd3d-proton:vkd3d_supports_minimum_coop_mat_caps Missing sufficient features to expose WMMA.
err:vkd3d-proton:vkd3d_create_vk_device Failed to create Vulkan device, vr -3.
fixme:vkd3d-proton:hresult_from_vk_result Unhandled VkResult -3.

This immediately triggers an unhandled exception page fault inside eldenring.exe at 0x1e9f54b due to a null pointer dereference (EXCEPTION_ACCESS_VIOLATION reading 0x0000000000000000 at 0x006ffff805f54b).

It appears VKD3D-Proton is missing dxgi format mappings (0x70 through 0x84) that the game expects when running on Blackwell, causing the device creation to fail and subsequently crashing the game. Has anyone else running RTX 50-series hardware under Linux hit this specific vr -3 failure in Elden Ring? Is there a pending vkd3d-proton patch for these missing formats?