I'm having an issue with this mission. I'm at the part where you have to continue traveling with MacCready. I traveled with him for a long time now but he's still not talking to me about what to do next. Don't we supposed to go to the Med-Tek Research?

You have to get his affinity up by doing things he "likes" and then he will give you the rest of the mission. I'm in the same boat trying to get his affinity towards me up.