I think this issue was caused by a mod called warmonger, it causes the mod's krastorio-style creep to fail to expand sometimes and a crash shown below to happen

The mod Restrictions on Artificial Tiles (0.8.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event RestrictionsOnArtificialTiles::on_tick (ID 0)
RestrictionsOnArtificialTiles/control.lua:47: attempt to index field 'items_to_place_this' (a nil value)
stack traceback:
RestrictionsOnArtificialTiles/control.lua:47: in function 'removeInvalidTiles'
RestrictionsOnArtificialTiles/control.lua:119: in function 'process_entity'
RestrictionsOnArtificialTiles/control.lua:228: in function 'process_entities'
RestrictionsOnArtificialTiles/control.lua:520: in function <RestrictionsOnArtificialTiles/control.lua:514>

Thanks for the report. Seems like I made a bad assumption in the control code. I'll take a look and load this along side warmonger to see what exactly is causing it, too.

This should be fixed with 0.8.4.

I also noticed another unintended affect on that mod and have posted to the warmonger discussions with a fix.

thank you! i love this mod, it really helps my OCD and lets he have little (short-lived with the pollution) decorative trees and gardens around my base without having to focus too hard on where i put the tiles.

Hey there! Thanks for making this mod, my immersion is restored!

Quick feedback related to this, when playing with K2, I noticed the creep tiles under spawners were also removed, leaving behind an outline circle of creep around the spawners

Yeah, that's the "another unintended affect" I noticed with Warmonger. Maybe I need to switch up how it does its detection. I just want to avoid hard-coded lists.