"FingerX2" bones cause SFM and it's SDK to crash.

Good afternoon.

I am trying to compile a ragdoll model (vestless and regular Francis) for SFM, but it always crashes SFM and it’s SDK when i try to load the model. Funny enough, it works just fine in the L4D2 SDK that i have.
But the weird thing is, as soon as i remove all of the “ValveBiped.Bip01_X_FingerY2” it works just fine.

I already tried moving the bones around and using “$renamebone” to change the name from a custom name to the original name (since i want this to be usable for Gmod’s finger poser aswell), but that doesn’t work either.
I know it should be possible because the original Francis model works fine with the same armature.

Does anyone know a way to fix this issue without having to delete those bones?

~Cheers