Odd. I've never seen this. Did you try re-downloading? What OS are you using? I'll bug hunt this for you this morning and let you know if I have an answer.
Hey there! Thanks for the response. I wouldn't recommend looking into this too deply for me, though. I spent many hours today trying to figure this out and I think there are some compatibility issues between DirectX and my graphics card, or that I have hardware issues. I have found that I have issues on many other games as well, not just yours!
Try this: https://itch.io/t/442958/fatal-error-in-vertex-shader-compilation-solved
This might help with other directX issues.