Hi! First of all thanks for this mod!
I've been using this mod with Space Exploration in Factorio 1.1 combined with Jetpack mod https://mods.factorio.com/mod/jetpack
The issue I have is that the game crashes whenever Jetpack gets activated or deactivated while having a waypoint set to be tracked with navigation arrow.
This is the error I get:
"
The mod Map tag core (0.1.5) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event map-tag-core::on_tick (ID 0)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
[C]: in function 'index'
__arrowlib/lib/position.lua:70: in function 'get_normalized'
arrowlib/scripts/controller.lua:19: in function 'get_pt'
arrowlib/scripts/controller.lua:42: in function 'calculate_relative'
arrowlib/scripts/controller.lua:90: in function 'calculate_prop'
arrowlib/scripts/controller.lua:173: in function 'tick_update'
arrowlib/arrow.lua:115: in function 'tick_update'
map-tag-core/scripts/gps.lua:298: in function 'tick_update'
map-tag-core/control.lua:39: in function <map-tag-core/control.lua:38>
"