Mods in question that caused this

Lost Factories
The Ruins mod
Factorissimo 2 (this)

Settings:
Lost factories:
Start up - Allow all buildings outside [x]
Map - Viable chunks per factory [30]
- Tier 2 minimum distance [600]
- Tier 3 minimum distance [800]

The ruins mod:
Map - Chance for small ruin [0.05]
- Chance for medium ruin [0.05]
- Chance for large ruin [0.05]

and just in case I mention also RSO ( resource spawn overhaul )
and other 50+ mods

reproduce ability: rare, random

What happened:
Lost factories is placeing factories, The ruins mod is placeing ruins. Usualy these dont interfier each other. One time when I was exploring the map I saw an factory and ruins overlaping with each other.
But this time something went wrong. Of course after reloading the save and went to the same place the issue not happened.

The mod The Ruins Mod (1.1.6) caused a non-recoverable error.

Please report this error to the mod author.

Error while running event AbandonedRuins::on_tick (ID 0)

The mod Factorissimo 2 - notnotmelon fork (1.2.3) caused a non-recoverable error.

Please report this error to the mod author.

Error while running event factorissimo-2-notnotmelon::script_raised_built (ID 79)

LuaEntity API call when LuaEntity was invalid.
stack traceback: [C]:
in function 'index'
__factorissimo-2-notnotmelon/control.lua:240:
in function 'power_pole_placed'
factorissimo-2-notnotmelon/control.lua:677:
in function <factorissimo-2-notnotmelon/control.lua:656>
stack traceback: [C]:
in function 'create_entity'
AbandonedRuins/spawning.lua:45:
in function 'spawn_entity'
AbandonedRuins/spawning.lua:94:
in function 'spawn_entities'
AbandonedRuins/spawning.lua:172:
in function 'spawn_ruin'
AbandonedRuins/spawning.lua:184:
in function 'spawn_random_ruin'
AbandonedRuins/control.lua:58:
in function <AbandonedRuins/control.lua:53>

The Ruins Mod does not receive Bug notifications so I dont know where to report it if it is that mod fault.