Debug Assertion when going underground for the first time.

[jlnunez89]

Clients affected: [Tibia 7.72]

Happens when the client gets a notification that places a creature before it gets the notification that describes the map.

Currently this is common because the game sends such notifications on monster spawning, which happens when a window is loaded, which happens when the first player "explores" the map tiles underneath.

So in general, the player moving must get their own notification before any other creature's notification.