The mod Transport Drones (1.0.10) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Transport_Drones::on_configuration_changed
Given entity doesn't exist anymore.
stack traceback:
[C]: in function 'set_command'
Transport_Drones/script/transport_drone.lua:666: in function 'go_to_depot'
Transport_Drones/script/transport_drone.lua:165: in function 'pickup_from_supply'
Transport_Drones/script/transport_drone.lua:861: in function 'on_configuration_changed'
core/lualib/event_handler.lua:87: in function <core/lualib/event_handler.lua:84>

When loading a save file. I can supply them if you want (reminder for self: #67, #68, autosave1). The crash is reproducible and happens while the screen is still black from loading.