crash because of megamorph mod

[berengma]

2020-10-08 15:48:37: ERROR[Main]: ServerError: AsyncErr: Lua: finishGenRuntime error from mod 'megamorph' in callback environment_OnGenerated(): .../.minetest/games/exile/mods/megamorph/geomorph.lua:434: attempt to index field '?' (a nil value)
2020-10-08 15:48:37: ERROR[Main]: stack traceback:
2020-10-08 15:48:37: ERROR[Main]: .../.minetest/games/exile/mods/megamorph/geomorph.lua:434: in function 'write_cube'
2020-10-08 15:48:37: ERROR[Main]: .../.minetest/games/exile/mods/megamorph/geomorph.lua:295: in function 'write_shape'
2020-10-08 15:48:37: ERROR[Main]: .../.minetest/games/exile/mods/megamorph/geomorph.lua:283: in function 'write_to_map'
2020-10-08 15:48:37: ERROR[Main]: ....minetest/games/exile/mods/megamorph/mapgen.lua:199: in function '?'
2020-10-08 15:48:37: ERROR[Main]: /usr/local/share/minetest/builtin/game/register.lua:429: in function </usr/local/share/minetest/builtin/game/register.lua:413>

[DokimiCU]

megamorph confuses they hell out of me. (it's someone else's exceedingly complicated code.)

My chances of fixing this are low...