Hello there @Teriander!
Checking around the community, there have been a few cases of this problem. And indeed, the cause is usually tied to substrate. In order to resolve the issue, we can try the following:
- First, go to Project Settings > Rendering and confirm “Substrate Materials (beta)” is enabled. Restart UE, and let shaders fully recompile.
- Next, please make sure “Virtual Texture Support” and “Virtual Texture Lightmaps” are enabled as well.
- If the issue persists, clear the shader cache, via deleting folder “DerivedDataCache” from your project directorty, then recompile.
- You can also test disabling all Metahuman plugins, then re-enable the creator only, followed by its dependencies in another restart.
For more details, please check the thread below: