Project Won't Open With Vulkan Settings

Development Getting Started & Setup
1

Has anyone ever gotten this when trying to open a project where the targeted RHI is Vulkan?

Fatal error: [File:D:\build++UE5\Sync\Engine\Source\Programs\ShaderCompileWorker\Private\ShaderCompileWorker.cpp] [Line: 61]
Mismatched shader version for format PCD3D_SM6: Found version 1677771108 but expected 2237508375; did you forget to build ShaderCompilerWorker?

My projects were opening earlier and then all of a sudden they cannot open and give this error. When I change the DefaultEngine config to make DirectX12, the project opens fine and shaders compile.

1 Like
2

I have the same error, I have been trying to even rebuild the entire machine and still nothing, the weird part is that happens completely random, I had several projects with RHI default in Vulkan they were opening fine, once the error happens all the vulkan projects won’t open and I will get that message. Only way to open the project is to switch back to DX12 which is a palliative solution, as we really need to see the vulkan shaders. I have been trying to look online for answers but there is nothing substantial on how to address this issue

3

This is a year late, but I ran to a similar problem where I set the Default RHI in Unreal 5 to Vulcan and the project does not open anymore.
This is the solution that worked for me:
You can override the Default RHI on launch without opening the editor and Force the project to use DirectX12

  1. Navigate to your project’s Config folder.
  2. Open DefaultEngine.ini with a text editor.
  3. Look for or add the section:
[/Script/WindowsTargetPlatform.WindowsTargetSettings]
DefaultGraphicsRHI=DefaultGraphicsRHI_DX12
  1. Save the file.
  2. Relaunch the project.