Building MGFX shaders in a shared GameLib project and consuming them from a platform-specific project (Windows) can lead to platform mismatch issues due to reused or improperly separated content outputs.

1

Title

MGFX shader built in shared GameLib project causes platform mismatch at runtime in Windows project

Description

I am encountering a platform compatibility issue when building .fx (MGFX) shaders inside a shared GameLib project and then running the game from a Windows-specific project.

Issue

The shader is compiled in the GameLib project via the Content Pipeline, and the Windows project references this compiled content. However, at runtime, the following error occurs:

This MGFX effect was built for a different platform!

Details

  • The .fx file is included and built in the shared GameLib project

  • The Windows project references GameLib and runs the game

  • MGCB is invoked during the Windows build with /platform:Windows

  • However, the shader appears to have been previously built (or cached) for a different platform (e.g., DesktopGL)

This suggests that:

  • Content built in a shared project is not properly isolated per platform

  • Intermediate or output files may be reused across different platform builds

Observations

  • The same .fx file works correctly when rebuilt cleanly for the target platform

  • The issue is more likely to occur when:

    • switching between DesktopGL and Windows

    • sharing Content across multiple projects

    • not cleaning bin/obj directories

Expected Behavior

  • Content built for one platform should not be reused for another platform

  • The pipeline should either:

    • isolate outputs per platform reliably

    • or warn when mismatched content is being loaded

Suggested Improvements

  • Better separation of platform-specific content outputs in multi-project setups

  • Automatic invalidation of cached MGFX binaries when platform changes

  • Clearer diagnostics indicating which platform the shader was built for

Summary

Building MGFX shaders in a shared GameLib project and consuming them from a platform-specific project (Windows) can lead to platform mismatch issues due to reused or improperly separated content outputs.

2

Set your output path to include the platform. I.e. bin/$(Platform)/ And the same for intermediate obj path.

I thought this was the default for precisely this reason :thinking:

3

“The .fx file is included and built in the shared GameLib project”
How are you doing this? Can you share the contents of your csproj? And how that “shared” gamelib is setup.

This is not standard practice.