Why isn't velocity working in a server, but it works in test mode?

I think I may have figured out your issue.

math.randomseed(tick(1))
touch = true
canRemove = {"RightUpperLeg","RightUpperArm","LeftUpperLeg","LeftUpperArm"}

function Applyforce(par,vel)
	local Forc = Instance.new("BodyVelocity")
	Forc.Parent = par
	--wait(.1)
	Forc.Velocity = vel
	wait(.2)
	Forc:Destroy()
end

function onTouch(PART)
    if touch then
        touch = false
        --Variables--
        local char = PART.Parent
        local humanoid = char:FindFirstChild("Humanoid")

        --Explosion effect--
        local boom = Instance.new("Explosion", script.Parent)
              boom.Position = script.Parent.Position
              boom.BlastRadius = 0
              boom.BlastPressure = 0
        local boomSound = script.Parent:WaitForChild("Boom")
        boomSound:Play()

        --Find, and kill player--
        if humanoid ~= nil then
            humanoid.Health = 0
        end

        --Launches player's body into air--
        local torso = char:FindFirstChild("LowerTorso")
		for I, v in pairs(char:GetChildren()) do
			wait()
	        if torso then
				local apf = coroutine.wrap(Applyforce)
	            --torso.Velocity = Vector3.new(math.random(-50,50), 250, math.random(-50,50))
				--[[apf(torso, Vector3.new(math.random(-50,50), 250, math.random(-50,50)))
	            torso.RotVelocity = Vector3.new(math.random(-50,50), math.random(-50,50), math.random(-50,50))
	        else
	            PART.Velocity = Vector3.new(math.random(-50,50), 250, math.random(-50,50))
				            PART.RotVelocity = Vector3.new(math.random(-50,50), math.random(-50,50), math.random(-50,50))]]
				if v:IsA("Part") or v:IsA("MeshPart") then
					apf(v,Vector3.new(math.random(-50,50), 250, math.random(-50,50)))
				end
	        end
		end

        if math.random() < 0.60 then
            for i = 1, 10 do
                wait()
                local children = char:GetChildren()
                local removeJoint = children[math.random(#children)]
                for _,name in pairs(canRemove) do
                    if removeJoint.Name:match(name) then
                        if removeJoint.Name == name then
                            removeJoint = char:FindFirstChild("RagdollConstraint"..name)
                        end
                        if removeJoint then
                            removeJoint:Destroy()
                        end
                        break
                    end
                end
            end
        else
            print("No limbs blown off.")
        end
        wait(1)
        touch = true
    end
end

script.Parent.Touched:connect(onTouch)

I tested this in a game and I figured out the issue is velocity itself and server latency. So I decided to make a coroutine using body velocity. And the result seemed to have worked in server.

Comment back if it works the way you want it to.