Skinned mesh rendering black - seems like limit on # of materials?

Hi,

As the title suggests I am having a problem with the rendering of a skinned game character. Parts render as black. It seems like theres a limit on number of materials. This is in the hololens Emulator not the actual headset. (headset hasn't arrived yet).

I tried changing from unity standard shaders to mobile diffuse ones but it made no difference. The character uses 7 different materials but only some of them are rendering. If i assign 1 material for everything then it all renders fine. I have also tried adjusting the quality settings to fantastic but it didnt do anything.

To solve this I will likely just merge the textures into one map so i can use less materials .
BUT I'm just curious if anybody knows wether its a hard limit on number of materials or whether theres something I can do to allow more. I can't seem to find anything about it in the documentation.

Below are pictures of what I am talking about.

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