The mod Kruise Kontrol Updated (0.2.6) caused a non-recoverable error.

Error while running event Kruise_Kontrol_Updated::on_tick (ID 0)
Key "layers" not found in property tree at ROOT
stack traceback:
[C]: in function 'request_path'
...d__/script/character_interface/states/moving_vehicle.lua:95: in function 'request_path'
...d__/script/character_interface/states/moving_vehicle.lua:317: in function 'update'
...ntrol_Updated__/script/character_interface/character.lua:51: in function 'update'
...ntrol_Updated__/script/character_interface/character.lua:685: in function 'handler'
core/lualib/event_handler.lua:47: in function <core/lualib/event_handler.lua:45>

Occurred when I was flying in an attack helicopter (HelicopterRevival 0.3.0) and I activated Kruise to lay some railway track, which would also involve chopping some trees or rocks in the way.

Game 2.0.23, 80769 expansion, win64.

Crash is 100% repeatable on 2nd and further attempts.

Turns out it has nothing to do with railway. To cause it just play a ribbon world, fly the heli off the edge of the world into the black void (really handy feature in that mod), and activate Kruise to e.g. chop trees.

Doesn't crash if heli is over land when activating Kruise to chop trees (or any other goal). Instead just says "moving to x,y" and does nothing. That's OK. But crashes if flying in the void.

I also got this one:

Error while running event Kruise_Kontrol_Updated::on_tick (ID 0)
Key "layers" not found in property tree at ROOT
stack traceback:
[C]: in function 'request_path'
...d__/script/character_interface/states/moving_vehicle.lua:95: in function 'request_path'
...d__/script/character_interface/states/moving_vehicle.lua:317: in function 'update'
...ntrol_Updated__/script/character_interface/character.lua:51: in function 'update'
...ntrol_Updated__/script/character_interface/character.lua:685: in function 'handler'
core/lualib/event_handler.lua:47: in function <core/lualib/event_handler.lua:45>

Occurred when I was flying in an attack helicopter OVER LAND, not the void. I looked at a distant part of the world in map view, and activated Kruise to move to a piece of land there. It crashed instead.

I will take a look into compatibility with that mod when available.

Tried the same case using a Hovercraft. It drives the hovercraft very poorly of course, but it doesn't crash.

I was not able to replicate this, would it be possible for you to upload a save and tell me where to click for the crash?
I tried clicking
while in the void - to the void, into the map, on a ghost
while in the map - to the void, into the map, on a ghost
both in a helicopter and hovercraft

Wow. I reloaded the game I saved that day, in case you did ask for one. Neither of those cases I described will crash any more. It just flies to there instead.
Excellent. Maybe the newer versions aren't vulnerable?? Or, somebody else updated their mod, maybe the helicopter mod. It's hard to know what helicopter version number I was running at the time, except maybe by the date??

You said Helicopter version 0.3.0 in the first post and that mod hasn't updated in 2 months so i'm thinking it's related to a game update.