The mod Transport Drones (1.0.4) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Transport_Drones::on_robot_mined_entity (ID 65)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
[C]: in function 'newindex'
__Transport_Drones/script/depots/supply_depot.lua:134: in function 'on_removed'
Transport_Drones/script/depot_common.lua:298: in function 'remove_depot'
Transport_Drones/script/depot_common.lua:308: in function 'handler'
core/lualib/event_handler.lua:47: in function <core/lualib/event_handler.lua:45>