I am super new to scripting and know next to nothing about it, so when you answer my question you might have to dumb down the answer. But anyways, my friend asked me to fix this ROBLOX gear called the luger, So I open up ROBLOX and first tried to see what was causing it to not work. After getting it to break and checking the console it said: "This mouse is no longer active." I didn't really know what to do so I came here. I looked around and it seems like a lot of people were saying its a really annoying un-fixable problem but I thought I'd ask anyways. Here are the things: 

function GunObject:Reload()
	self.Reloading = true
	self.ReloadingVal.Value = true
	if self.Clips ~= nil then
		if self.Clips.Value > 0 then
			self.Clips.Value = Clips.Value - 1
		else
			self.Reloading = false
			self.ReloadingVal.Value = false
			return
		end
	end

and

function GunObject:SendBullet(boltstart, targetpos, fuzzyness, SegmentLength, ignore, clr, damage, fadedelay)
	if self.Ammo.Value <=0 then return end
	self.Ammo.Value = self.Ammo.Value - 1
	self:SpawnShell()
	self.Fire.Pitch = (math.random() * .5) + .75
	self.Fire:Play()
	self.DoFireAni.Value = not self.DoFireAni.Value
	print(self.Fire.Pitch)
	local boltdist = self.Range
	local clickdist = (boltstart - targetpos).magnitude
	local targetpos = targetpos + (Vector3.new(math.random() - .5, math.random() - .5, math.random() - .5) * (clickdist/100) * self.fuzzyness)
	local boltvec = (targetpos - boltstart).unit
	local totalsegments = math.ceil(boltdist/SegmentLength)
	local lastpos = boltstart
	for i = 1, totalsegments do
		local newpos = (boltstart + (boltvec * (boltdist * (i/totalsegments))))
		local segvec = (newpos - lastpos).unit
		local boltlength = (newpos - lastpos).magnitude
		local bolthit, endpos = CastRay(lastpos, segvec, boltlength, ignore, false)
		DrawBeam(lastpos, endpos, clr, fadedelay, self.LaserObj)
		if bolthit ~= nil then
			local h = bolthit.Parent:FindFirstChild("Humanoid")
			if h ~= nil then
				local plr = game.Players:GetPlayerFromCharacter(self.Tool.Parent)
				if plr ~= nil then
					local creator = Instance.new("ObjectValue")
					creator.Name = "creator"
					creator.Value = plr
					creator.Parent = h
				end

The two lines it is complaining about are 2 and 19

Anonymous