Map generation fails with TypeError

[chrbinder]

When loading a heightmap file with python3 generate_map.py --heightmap=parsed_data/heightmap.dat , I'm getting this error:

from 706000,5706000 to 708000,5708000 (size: 2001,2001) Traceback (most recent call last): File "/home/user/world2minetest/generate_map.py", line 122, in <module> if not (min_x <= args.offsetx <= max_x and min_y <= args.offsetz <= max_y): TypeError: '<=' not supported between instances of 'int' and 'NoneType'

DGM data has been taken from here: https://www.lvermgeo.sachsen-anhalt.de/de/dgm2.html