You can't switch between levels this way, because when loading a level, the current level will be closed and all entities within will be removed.
That's principle of levels in Acknex.
# The current level is closed, the cache holding level entity files is purged. All current entities in the old level are removed, thus all entity pointers referring to them can't be used anymore. For preventing an entity file from being purged at level change - which could make sense for speeding up level loading - define it as a view entity.
