Problems:

When I publish, the error string: "rbxassetid//[assetid] failed to load in Animation.AnimationId" or It doesn't work in studio 90% of the time.

Not my script, but it doesn't seem to work when I publish to ROBLOX.

The Explorer list is

Workspace |_ | Seat |_ | Script |_ | Sitanim

seat = script.Parent
function added(child)
	if (child.className=="Weld") then
		local.human = child.part1.Parent:FindFirstChild("Humanoid")
		if human ~= nil then
			anim = human:LoadAnimation(seat.sitanim)
			anim:Play()
		end
	 end
end

function removed(child2)
	if anim ~= nil then
		anim:Stop()
		anim:Remove()
	end
end

seat.ChildAdded:connect(added)
seat.ChildRemoved:connect(removed)