UE4.27.2 Changing Skeletal Mesh in Game and Materials don't render

Hi

I am working with UE4.27.2. I want to change my character’s hair in game. I have used two approaches:

  • Create and assign Dynamic Materials to the skeletal mesh and change the texture of the dynamic material
  • dynamically change the skeletal mesh asset

In both cases the result is that the skeletal mesh is rendered dark grey as if the engine couldn’t work out the rendering at all. Without the dynamics, the hair renders correctly. I have used the technique to create dynamic material instances and change textures before with face, arms and legs and so on and it worked great. Just with the hair it doesn’t work at all. One more thing: Changing the Skeletal Mesh works for a different Hair Model. It doesn’t work for one specific model (which is quite complex) - so I assume it is a performance issue.

Any ideas what could be the reason? What shall I check and how to fix it? Thank you for your help!