I’m in the middle of integrating my nodes-rotating algorithm with my insertion algorithm until this error emerge. After the balancing function return a new node to replace the old one, the recursion stopped after 1 or 0 node. I put a couple of printf() to backtrack the problem but i still don’t find a clue what’s going on. Is this one of those scenario where the problem is just unexplainable? thanks for your time reading this post.