I looked through the logs myself and found the error messages related to building the master materials list. This comes up for pretty much every material it finds:
- [2017.06.19-22.36.45:617][ 14]LogMaterial:Warning: (Node TextureSampleParameter2D) Param2D> Requires Texture2D
- [2017.06.19-22.36.45:717][ 15]LogMaterial: Missing cached shader map for material BaseMaterial, compiling.
- [2017.06.19-22.36.45:718][ 15]LogMaterial:Warning: Failed to compile Material Instance /Game/SourceStuff/Materials/metal/metaltruss024a_mat.metaltruss024a_mat with Base BaseMaterial for platform PCD3D_SM5, Default Material will be used in game.
This happened with the sample base material provided in the sample materials zip as well.