It seems out of nowhere suddenly this weird green shade is on the back half of Imperial Assault's R5 astromech droid model... I noticed something similar with the AT-ST in that when it shoots a shade of purple shows up on the back of the model every time it shoots.
Anyone know why this is happening and/or how I can fix it?
I believe you have some type of color applied to the material with the Renegade tools. You'll just want to use a neutral grey, and re-export the model. That should fix it.