Just updated the newly released K2, and I get this error, when I sync and load my old game with the same mods.

The mod Mining Drones (2.0.2) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Mining_Drones::on_configuration_changed
Mining_Drones/script/mining_drone.lua:529: attempt to call method 'return_to_depot' (a nil value)
stack traceback:
Mining_Drones/script/mining_drone.lua:529: in function 'validate_proxy_orders'
Mining_Drones/script/mining_drone.lua:634: in function 'on_configuration_changed'
core/lualib/event_handler.lua:87: in function <core/lualib/event_handler.lua:84>

it is worth noting, that this only seems to apply to any game, where I already placed and used the drones.

In a clean game, this does not seem to be a problem.