The Waypoints in the map should be recalculated: some of them, e.g. "Framsburg" in the region "Vales of Anduin" let me spawn some meters under ground and I died ... and then the game crashed. After restarting the game in creative-mod I could dig myself up to the ground. I guess some of the y-coordinates have changed since the last updates. It happend several times.
When you fast travel to a permanent waypoint, it checks for the highest block where that waypoint is and then spawns you on top of it. However, in some cases when you are fast traveling into new chunks, I think it does this check a little too early and generation such as boulders and trees aren't generated yet so they don't get calculated in the height and you may end up inside of one.
Many thanks for the fast reply, the Admins here are really great, but I think, the game should pause until the surrounding elements are all created and done. And in the previous updates all was fine - something might have changed. And perhaps it should be calculated before spawnig, if it will be underneath the earth - kind of usual error tracking - and then being recalculated.
When I coded the rndtp mod, I expected to have to check for all trees wood and foliage in order to put people safely on the ground, but when teleporting into an ungenerated chunk, when you place the player at the destination before sending the update to the player side in order to generate the chunk, the terrain is not "populated" with trees and other "decor" so it's not necessary.
Of course, for players teleporting afterwards at the same location, they might appear on top of a tree, but it never happened in my tests.
When you add the LOTR mod, the only additional effect was that the mod could decide to build a structure just at your location, and you could find yourself underground. It happened to me a few times in Mordor.