Seem to have the same issue
The mod The Ruins Mod 2.0 (1.1.12) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event AbandonedRuins20::on_tick (ID 0)
__AbandonedRuins20__/lua/spawning.lua:38: attempt to index global 'data' (a nil value)
stack traceback:
__AbandonedRuins20__/lua/spawning.lua:38: in function 'spawn_entity'
__AbandonedRuins20__/lua/spawning.lua:98: in function 'spawn_entities'
__AbandonedRuins20__/lua/spawning.lua:176: in function 'spawn_ruin'
__AbandonedRuins20__/lua/spawning.lua:188: in function 'spawn_random_ruin'
__AbandonedRuins20__/control.lua:58: in function <__AbandonedRuins20__/control.lua:53>