Game Crashes randomly

I've had this problem for quite some time now. But right now I struggle with it the most. When im playing my game seemingly random just crashes sometimes. Most of the time when im flying into a new zone or entering Dalaran. But now Im doing the Sons of Hodir Questline and I have to use some Quest Item to grapple some Dragons and kill their riders. And now my game crashes everytime when im using the item. I cannot explain why it does that and I really need help. I do not know where I should ask for help on this problem. Thats why Im trying it here. I tried looking for a solution online but I didnt find anything that helped me. I also read that I had to delete my WTF folder. I did that and reconfigurated my Addons. I were able to kill 2 mobs after that and then my Game again kept crashing everytime I used the Quest item. I really need help with this otherwise I cant keep playing on this Server. And that would be very Sad because I really liked it here.

(Note: Im not using any kind of Graphic enhancement modifications or programs like WoD models)

Quite possible that a file is corrupted. Either force recheck if you still have the torrent active or redownload the game.