No NG+ after Gwyn?

So I just discovered a weird glitch. I just played through the entire game, and defeated gwyn. Normally, this would send me straight into NG+. But this time, it just teleported me back to firelink. No NG+. Bosses and NPC's were still dead, areas still unlocked, i'm just back in my same game. And now, whenever i try resting at a bonfire, the game freezes and crashes. What happened?

EDIT: Solved the problem. It's because I had a bonfires mod installed and it was battling the game files. Deleted the mod and all is well.