Ported Model Issues

So I’ve recently started learning how to port/rig my own models.

I have this one here almost fully functional, but there is an issue with the calf bone on the model literally only being turned 90 degrees one direction, whilst the rest of the model is 100% A-okay as far as its direction.

Any help/comments is GREATLY appreciated, as I’m at a brick wall until sorted.

Turns out anything that I apply weight painting to is stuck in some different direction outside of the base model.

If i start attaching the pieces back to it, the are also turned like the calves.

Is there something I’m missing when setting some type of parent or direction the pieces should be based off of?

If you are using Blender, make sure the Auto-normalize box is checked when weight painting