Model:SetPrimaryCFrame() failed because no PrimaryPart has been set?

When i run the script it comes up with "Model:SetPrimaryPartCFrame() failed because no PrimaryPart has been set, or the PrimaryPart no longer exists. Please set Model.PrimaryPart before using this. - Server - Script:7". I Have no idea how to fix this, any help ?

_G.deadzombies = 0

local ServerStorage = game:getService("ServerStorage")
local Zombie = ServerStorage:WaitForChild("Zombie")

local newZombie = Zombie:Clone()
newZombie:SetPrimaryPartCFrame(CFrame.new(10,10,10))
newZombie.Parent = game.Workspace.Zombiez

while wait(1) do
    if #game.Workspace.Zombiez:GetChildren() == 0 then
        for i = 0, _G.deadZombies, 1 do
            print("looping")
            local newZombie = Zombie:Clone()
            local myCFrame = game.Players.LocalPlaye
            newZombie:SetPrimaryPartCFrame(CFrame.new(math.random(1,100),10,math.random(1,100)))
            newZombie.Parent = game.Workspace.Zombiez
        end
    end
end