The mod Combat Robot Overhaul (2.1.19) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event CombatRobotsOverhaul::on_nth_tick(60)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
[C]: in function 'get_closest'
CombatRobotsOverhaul/scripts/destroyergroup.lua:43: in function 'update'
CombatRobotsOverhaul/control.lua:287: in function <CombatRobotsOverhaul/control.lua:280>

Got that after trying to deploy a large group of Legendary Destroyers to take out a Demolisher.

Looks like there is an invalid entity in the target list. You should be able to remove it by using the command: /combatrobotoverhaul-clean-invalid.

Destroyer can't be damaged by demolisher for some reason while vanilla one can even get damaged by the smoke cloud. Pretty funny to have a worm that chasing a bunch of fly forever.

https://files.catbox.moe/n5ur0j.mp4

I assume this was due the lack of collision layers. I set them to zero a while back since the robots took damage when flying over acid on the ground. It seems, however, that this particular effect has been changed. Hence why I have disabled the lack of layers. Now the robots take damage from fissures

Since there were issues with the path finding I have readded the empty collision layers. This means that the smoke cloud and fissures won't be able to target tthe combot robots.

It's fine they are basically useless vs worm either way lol. I love deploying these on Gleba early after ariving it though. These mf after a bunch of research clear enough of the map that I think I don't need to do genociding for another 100 hrs.