!! Attention after the upgrade from b0.24 if the server should not start anymore !!!

The problem is that a mod was removed which unfortunately has written itself in almost everywhere but there is a workaround:

backup world folder (the easiest way is to create a zip from it)

empty world folder (delete completely)

start sever

stop server

copy (almost) everything from the backup (world.zip) folder into the world folder (overwrite) Extract level.dat level.dat_old session.lock

start server

continue playing

Sorry for the inconvenience