Why does weight painting this skeleton with reverse kinematics rotate the vertex around the bone I have a skeleton that I added reverse kinematics to because I have no idea what I'm doing, I watched a tutorial, and it seemed like a good idea. I needed to rotate the bone position so that the knee was bending correctly, so I added a rotation to it. 

Presently, When I try to weight paint any of the upper leg vertices, they rotate inward 90 degrees. It seems that the bone rotation is being applied to the weight painting. How do I keep it so that the Knee still bends correctly, but the weight painting doesn't distort the vertices like this?
See a gif below, and the .blend file.

Thanks in advance!
Go into the armature pose mode, select every thing with A then press Ctrl + A and "apply pose at rest pose".

Your bone constraints moved the bones in pose mode a little so you need to apply  their new transforms as the official "rest pose"