I'm still using 1.5

The strange thing is, some of the Companions have turned hostile on me. Farkas and Ria especially both came after me. I was able to talk to Farkas and get a job from him, only after going invisible until he didn't detect me. Ria only can be spoken to under a Calm spell.

Why is this? What the hell is going on here?

I've had some other strange encounters with hostile NPCs that shouldn't have been hostile. Talsgar the Wanderer spawned a head of me and started attacking me. It was the strangest thing. I've had a Stormcloak Courier turn into a red dot, but he just kept going. Some guards would attack him though.