Board Thread:Bug Reports/@comment-108.63.183.43-20150606203422/@comment-25565811-20150615182434

That's normal until the chunks are loaded. When you wait a bit, you always slowly fall down (to about level 40) and then hop up again to level 100 or so, until the chunks are generated. Then you land on the surface (unless in very rare cases where you spawn underground and suffocate) and everything is ok.

Just be patient, world generation takes a while, especially in forest biomes like jungle or lothlorien. If you enter that point a 2nd time, it should be loaded quite fast, as all the chunks are already generated and need only to be loaded from the disk files.