It works with 2.1.20. Only crashes with 2.1.21.

69.289 Error AppManagerStates.cpp:2736: The mod Warptorio 3 (No Space Age) Expansion (2.1.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event warptorio3_2_expansion::on_init()
warptorio3_2_expansion/control.lua:900: attempt to concatenate local 'tempcap' (a nil value)
stack traceback:
warptorio3_2_expansion/control.lua:900: in function 'update_frame_planet'
warptorio3_2_expansion/control.lua:519: in function 'gui_init'
warptorio3_2_expansion/control.lua:454: in function 'rebuild_all_players_gui'
warptorio3_2_expansion/control.lua:406: in function 'setup_mod_vars'
warptorio3_2_expansion/control.lua:419: in function <warptorio3_2_expansion/control.lua:417>

Hmm. Just started new game, all works fine.
Maybe that caused by some third-party planet mod (except required)?

P.S. Which version of the mod are you playing?

Ouch, nevermind, I am an idiot. I started a new Tutorial instead of a new Freeplay. Cant believe I consistently made such a mistake with multiple tries xD