Two of the characters in my four character scene legs behave like they're trying to break off.
How it normally goes: 



But what happens to the other guy: 

Two of them work fine, but the other two character's legs spaz out at every movement.
The feet are locked for all the characters. Outside of that, there have no changes in the actors.
What did I do wrong?

Do you have any video about recording your issue?
If you can provide a video, I could help you to figure out and find other workarounds.

How did you do this?
I cannot reproduce your issue.
Could you provide your project on this forum?
OR you can pass your issue to Technical support they will help you. 
This issue needs a project for further investigation.

I honestly wish I knew how I did this. 
I bet it's something that can be easily fixed. I'll add the file here for anyone to see what the deal is. It's a Mega link; I hope that's OK.

Thanks a million! I knew you guys could figure it out, and it was super easy to fix.
Thanks again!