Textures and Materials Displaying Black in Content Browser and on Meshes (UE 5.5.1)

You may want to go back and review shader permutations now that it’s working. If nothing else, having a bunch of extra shader permutations will increase your compile times unnecessarily.

https://dev.epicgames.com/community/learning/knowledge-base/6PxP/unreal-engine-understanding-shader-permutations