Projectiles (the yellow balls) will not fire. Please help!

So I have just made it so that my projectiles will destroy destructible meshes but now when I try to shoot the balls just fall straight down without going forward at all, if I shoot multiple projectiles they will stack on top of each other. While it was amusing the first time it happened I would really like to fix this. After exiting the play screen this error message popped up.

invalid simulate options: Body(FirstPersonProjectile_C_6.CollisionComponent) is set to simulate physics hut Collision Enabled is incompatible

I was following a youtube tutorial so its possible that I missed a step or did it wrong but I have no idea how to fix it. Hopefully someone here does. I am using UE 4.10.4 Thanks in advance for your help.