Crashing while working with ALSV4 Character Blueprint

Crash Log

I was following this video (14:00 [Not a tutorial] Adding reload animation from starter animations pack to ALSv4 (Full Version) - YouTube) I was changing the values of the hand sockets and then I tried to play and it crashed. It crashes every time I play the level, or even left click once over the ALS_Character_BP. Very confused. Need help.