I know this topic is super old, but it was near the top of my Google results. I figured my input may help anyone who comes across this. I had the same issue. Go near Riften and my game would freeze. I ended up having to disable mods until I found the problem. Here is a link to my modlist on PasteBin with the offending mods removed. http://pastebin.com/yw05byUg What were the offending mods, you ask? Maybe OCS? Maybe a quest mod? Maybe a secret cities entrance mod? NO! It was bloody Apache Skyhair for NPCs. I guess no PC was meant to handle Brynjolf's luxurious wavy Fabio locks. http://pre12.deviantart.net/e4d3/th/pre/f/2014/276/c/5/skyrim__kate___brynjolf_by_eddyslilsis-d68tx1i.jpg