The mod Will-o'-the-Wisps updated (0.3.21) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Will-o-the-Wisps_updated::on_nth_tick(353)
LuaEntity belongs to surface Factory floor 16 (index 17) but a LuaEntity belonging to surface nauvis (index 1) was expected.
stack traceback:
[C]: in function 'set_command'
Will-o-the-Wisps_updated/control.lua:692: in function 'task_func'
Will-o-the-Wisps_updated/control.lua:711: in function 'run_on_object_set'
Will-o-the-Wisps_updated/control.lua:730: in function 'run_periodic_task'
Will-o-the-Wisps_updated/control.lua:762: in function <Will-o-the-Wisps_updated/control.lua:743>

I believe this happening regularly during the night when inside Factorissimo factory building. I did not notice any other pattern.

Edit: Crash take place at the same moment even if save is reloaded. Tried changing time to day using Clockwork mod, but crash still take place. So either time of day is irrelevant for this issue or the way Clockwork change time of day is somewhat funky.

However, game not crashing if during event character is not inside of factory. I do not know if surfaces from Factorissimo is a problem or if others non-nauvis surfaces (like ones from SE) also causing a crash. I think someone would have reported it by now if it were the case.

Thanks for reporting!

Looks like it should happen if you have a group of green wisps targetting player that moves to other game surface.
Code updating position didn't have a check for whether surface stayed the same, so using destination_entity=player failed like that.

Should be fixed in 0.3.22, maybe try loading that save where it always happened to make sure it's gone, jic.
(can also test it anytime by running /wisp congregate console cmd and once some group follows player, go inside factory and see what happens)

I think someone would have reported it by now if it were the case.

Yeah, it caused some issues in the past with Space Exploration mod and occasionally some code change doesn't take this into account.
This one is probably just rare, so no one else stumbled into it yet :)

Similar thing happened in https://mods.factorio.com/mod/Will-o-the-Wisps_updated/discussion/5f96da68033e6d67b2d5037c but that was when creating a group of wisps and picking random player, not re-targetting same player, which are different bits of code, and I didn't think of this case when fixing that one.

Thank you for quick update.

Unfortunately, I do not have this specific save anymore, nor were I able to make any green wisp follow me for same reason. I will keep this in mind, but hopefully update fixed crash and I have nothing to worry about.

nor were I able to make any green wisp follow me for same reason

It should be 15% chance, which you can tweak in config.lua, I'd guess just bad luck :)
But yeah, pretty sure it should be fixed anyway.

So, the new version crashes as well, although in a different way.

The mod Will-o'-the-Wisps updated (0.3.22) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Will-o-the-Wisps_updated::on_nth_tick(353)
Will-o-the-Wisps_updated/control.lua:679: attempt to call field 'position' (a table value)
stack traceback:
Will-o-the-Wisps_updated/control.lua:679: in function 'task_func'
Will-o-the-Wisps_updated/control.lua:710: in function 'run_on_object_set'
Will-o-the-Wisps_updated/control.lua:729: in function 'run_periodic_task'
Will-o-the-Wisps_updated/control.lua:761: in function <Will-o-the-Wisps_updated/control.lua:742>

This crashes taking place on nauvis surface, not inside the factory. First time I saw some green wisps around. I did not notice any before the second crash, but I was zoomed in at the time, so green wisps might have been off-screen.

Ah, apparently omitted one comma there somehow. My bad. Should be fixed in 0.3.23.
Guess none of these things also roll going to my position when I was testing earlier change for just that kind of basic bug, weird.

Thank you for the fix. I believe the issue is resolved now.