Why Is the mouse not being found?

Im trying to make a script that helps my building script to know where you will put your block,but when i try to use the mouse variable on the function to change the block position to the mouse position,this happens:

17:15:01.736 - Workspace.Player1B.FollowMouseScript:25: attempt to index global 'Mouse' (a nil value) 17:15:01.737 - Stack Begin 17:15:01.737 - Script 'Workspace.Player1B.FollowMouseScript', Line 25 17:15:01.738 - Stack End

Here's the script

Character = game.Workspace:FindFirstChild(script.Parent.Owner.Value)
if Character then
    print ("Character Found")
end
Player = game.Players:GetPlayerFromCharacter(Character)
if Player then
    print ("Player Found")
end
Mouse = Player:GetMouse()

if Mouse then
    print ("Mouse Found")
end
function FollowMouse()
    local MouseCFrame = Player:GetMouse()
            local x1 = math.floor(MouseCFrame.Hit.x)
            local y1 = math.floor(MouseCFrame.Hit.y)
            local z1 = math.floor(MouseCFrame.Hit.z)
            print (x1)
            print (y1)
            print (z1)
            script.Parent.Position = Vector3.new(x1,y1,z1)
            script.Parent.Rotation = Vector3.new(0,0,0)
end
Mouse.Move:connect(FollowMouse)

function RemoveBlock(PlayerName)

    if PlayerName == Player.Name then
        script.Parent:Destroy()
    end



end
game.Players.PlayerRemoving:connect(RemoveBlock)

It only works on studio solo,multiplayer online doesn't work with it