The skeletal mesh above is the gun? Is so, does it have an animation BP and is it set correctly ( Animation Mode and Anim Class)? Does the animgraph of the gun has a slot for the montage to play?
The skeletal mesh above is the gun? Is so, does it have an animation BP and is it set correctly ( Animation Mode and Anim Class)? Does the animgraph of the gun has a slot for the montage to play?