Got the same error, but it says in line 28 of /data/zombie_system.lua
function startZombie()
local specs = Game.getSpectators(zeWaitingRoomPos, false, true, 0, zeWaitingRoomRadiusX, 0, zeWaitingRoomRadiusY)
if Game.getStorageValue(zeJoinedCountGlobalStorage) == nil or 0 then...