Error with invisible model

I’ve been working on converting a model from MMD for use in Gmod, everything has been going well so far, but I got my model into the game and it is invisible, a quick look at the console gives the following error:

I don’t really understand this, could it have something to do with the fact that I removed the double vertices on the model, or that I transferred the weights from a default civilian model?
It could also be an issue with the model itself being modelled in layers, so there is the body, then clothes modelled over the body, rather than just having the clothes.

The fact that this error has shown up means I’ve probably done everything else right, as something unexpected has to happen or i’m not doing converting a model correctly.

Edit: could this issue be due to the conversion to an SMD file, is there a limit to the number of vertices a SMD model can have?