Zombie Spawner broke? Output error

You actually can't change the position of a model like that because models do not have a position property. The two ways to do this would be:

Use MoveTo.

MoveTo is basically what you're doing. It changes the position of every part in the model to the chosen Vector3. This is most likely the best choice.

local z = game.ReplicatedStorage.Zombie
local zc = z:Clone()
local fm = game.Workspace:FindFirstChild("Map")
local fs = fm:GetChildren("ZSpawn")

while true do
    wait(10)
        if fm then
            for i = 1,30 do
                zc.Parent = game.Workspace
                zc:MoveTo(fs.Position)
            print("Spawned")
        end
    end
end

Use CFrame.

CFraming a part in the model will set that part's position to a certain spot (and other parts in the model spawn relative). The reason this isn't the best is because the zombie may glitch out when spawning.

local z = game.ReplicatedStorage.Zombie
local zc = z:Clone()
local fm = game.Workspace:FindFirstChild("Map")
local fs = fm:GetChildren("ZSpawn")

while true do
    wait(10)
        if fm then
            for i = 1,30 do
                zc.Parent = game.Workspace
                zc.CFrame = CFrame.new(fs.Position)
            print("Spawned")
        end
    end
end

You can't set a part's position because that would break it's joint.

Hope this helped! If so, accept/upvote! If not, burn your computer down.

~Chem