Game crashes after NPC shoots

[ABBI?? 0]

Hi there. I am experiencing an issue with the Custom NPCs mod. When I give an NPC a gun and set them to attack mobs, upon shooting the mob the game crashes and I cannot enter the world again. My screen has also started acting weird after experiencing this crash. I tried to get the crash log with vanillafix, but it failed. Help ?

[ABBI?? 0]

The guns are from Flans mod btw