Was recommended WT2. Started a fresh world with WT2, saved, then added expansion and could not load the old save anymore. (It was only like 5 minutes into the game)

Warptorio related mods:
warptorio2_1.2.1.zip
warptorio2_expansion_0.0.27.zip
warptorio_cold_planets_0.0.3.zip
warptorio_exotic_planets_0.0.2.zip
warptorio_hot_planets_0.0.6.zip

The mod Warptorio2 Expansion caused a non-recoverable error.
Please report this error to the mod author.

Error while running event warptorio2_expansion::on_init()
__warptorio2_expansion__/control.lua:597: bad argument #1 of 2 to 'floor' (number expected, got nil)
stack traceback:
[C]: in function 'floor'
__warptorio2_expansion__/control.lua:597: in function 'update_frame_planet'
__warptorio2_expansion__/control.lua:351: in function 'gui_init'
__warptorio2_expansion__/control.lua:295: in function 'rebuild_all_players_gui'
__warptorio2_expansion__/control.lua:237: in function 'setup_mod_vars'
__warptorio2_expansion__/control.lua:242: in function <__warptorio2_expansion__/control.lua:240>

It is in the front page:
-you need to to start a new game to play this mod. Do NOT add it to saved games.

Eh. Well. That's what i did. But you might consider adding a check for game.tick == 1 in on_init and give a more useful error message if that is your policy.

You are right! =) I really should