The mod Alert Scanner (0.1.6) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event AlertScanner::on_tick (ID 0)
AlertScanner/control/Event.lua:123: attempt to index global 'Util' (a nil value)
stack traceback:
AlertScanner/control/Event.lua:123: in function 'update_surface'
AlertScanner/control/Event.lua:177: in function 'update_force'
AlertScanner/control/Event.lua:199: in function 'update_scanners'
AlertScanner/control/Event.lua:227: in function <AlertScanner/control/Event.lua:218>
If you use an upgrade planner to remove all ghosts on a surface you get a crash.