In single player survival, I customized a rare cities instance by using a building max height of 28 floor, with some tweaks to explosions (making large explosions higher).

World generation froze client at 71%, required an end task to restart.

crash log

When I restarted the client, the world appeared in the save game list and I was able to load it from there without reproducing the crash.

Did you enter another world before you create the new world? The current version only allows one world to be entered each time the game is launched. Otherwise, the world created/entered later uses the configuration of the first world created/entered after the game is launched. This will cause conflict and may crash.

Honestly - I have no idea, but will keep it in mind for the future. Thanks!