Can someone tell me what the problem is with my .Touched Event Part?

Can someone tell me what the problem is with my .Touched Event Part? I've tested this script multiple times and the Part Exp which is the large custom explosion radius in game?

Mouse.Button1Down:connect(function()
if not (ShootDeb) and (Ammo ~= 0) then
ShootDeb = true
Ammo = Ammo - 1
Missle = Instance.new("Part",Mod)
Missle.Name = "Missle"
Missle.Size = Vector3.new(1.6, 1.8, 4.2)
Missle.BrickColor = BrickColor.new("Really black")
MMesh = Instance.new("SpecialMesh",Missle)
MMesh.Name = "MMesh"
MMesh.MeshType = "FileMesh"
MMesh.MeshId = "http://roblox.com/asset/?id=2251534"
MMesh.Scale = Vector3.new(0.5, 0.6, 0.3)
Missle.CFrame = Hole.CFrame*CFrame.new(0,-7,0)
BodyV = Instance.new("BodyVelocity",Missle)
BodyV.maxForce = Vector3.new(math.huge,math.huge,math.huge)
wait(0.01)
Missle.CFrame = CFrame.new(Missle.Position,Mouse.Hit.p)
BodyV.velocity = Missle.CFrame.lookVector*130
Missle.Touched:connect(function(Hit)
BodyV:Destroy()
Exp = Instance.new("Part",workspace)
Exp.CanCollide = false
Exp.Anchored = true
Exp.CFrame = Missle.CFrame
Exp.Name = "Exp"
Exp.Locked = true
Exp.TopSurface = "Smooth"
Exp.BottomSurface = "Smooth" 
Exp.Shape = "Ball"
Exp.BrickColor = BrickColor.new("Bright yellow")
Exp.Transparency = 0.5
Exp2 = Exp:Clone()
Exp2.CFrame = Exp.CFrame
Exp2.Parent = workspace
Exp2.Name = "Exp2"
Exp2.BrickColor = BrickColor.new("Neon orange")
Exp3 = Exp:Clone()
Exp3.CFrame = Exp2.CFrame
Exp3.Parent = workspace
Exp3.Name = "Exp2"
Exp3.BrickColor = BrickColor.new("Bright red")
Missle:Destroy()
for i = 1, 24 do
wait(0.01)
Exp.Size = Vector3.new(i,i,i)
Exp2.Size = Vector3.new(i - 4 , i- 4 , i - 4)
Exp3.Size = Vector3.new(i - 6 , i- 6 , i - 6)
end
wait(0.01)
Exp:Destroy()
Exp2:Destroy()
Exp3:Destroy()
Exp.Touched:connect(function(Hit)
local FindH = Hit.Parent:findFirstChild("Humanoid")
if (FindH ~= nil) then
FindH.Humanoid:TakeDamage(math.random(40,78))
end
end)
game.Debris:AddItem(Missle,8)
wait(4)
ShootDeb = false
end)
end
end)

Your problem is coming from trying to connect an event to a nil value. You use the :Destroy() method on "Exp", which completely removes it from the game and disconnects any connections attached to it. Right after it was destroyed, you attempted to connect the Touched event to it, which will error because "Exp" doesn't exist. I would suggest moving it to a place before the for loop.

Hope this helped!