Still on my first playthrough on 360 and had this problem. Couldn't talk to him once I actually acquired the amulet. I was able to get to the cut scene with Solas twice where it would freeze and then I got locked out completely. Tried loading earlier saves, restarting the amulet map mission and the old fashioned stubborn route of I'll-just-keep-trying-until-it-works.
I had pretty much given up, continued along with other quests and such but kept checking back. Suddenly yesterday, it worked. Talked to Cole, no freezing. Completed his quest. Twice. The first time I tried mashing the X button repeatedly like I've read others did -- it never worked before. I ended up skipping through most of the scene until I had to choose a response. Played the quest again without pressing X and it went through without issue.
So... I have no idea. Maybe it fixed itself many, many, many hours later or after all my failed attempts or, maybe, Cole finally recognized my pain and fixed it for me. I guess I'll never know. -_- It would be nice if this didn't happen again.
