Hello Klonan, first of all, I really like factorio and Your mods. Thanks for Your work.
In my current save game of factorio the mod caused an exception on trying to load the save file. There were no errors encountered while playing before.
I use:
Factorio 0.18.19
Construction_Drones 0.4.11
Edit-Blueprints 0.1.0
FNEI 0.3.0
Krastorio2 0.9.11
Mining_Drones 0.3.19
Transport_Drones 0.5.7
even-distribution 0.3.17

Here is the error message:

Error while running event Transport_Drones::on_load()
LuaEntity API call when LuaEntity was invalid.
stack traceback:
Transport_Drones/script/depot_common.lua:204: in function 'get_lib'
Transport_Drones/script/depot_common.lua:209: in function 'load_depot'
Transport_Drones/script/depot_common.lua:349: in function 'on_load'
core/lualib/event_handler.lua:74: in function <core/lualib/event_handler.lua:70>
stack traceback:
[C]: in function 'index'
__Transport_Drones/script/depot_common.lua:204: in function 'get_lib'
Transport_Drones/script/depot_common.lua:209: in function 'load_depot'
Transport_Drones/script/depot_common.lua:349: in function 'on_load'
core/lualib/event_handler.lua:74: in function <core/lualib/event_handler.lua:70>

Can you provide the save game?

Yes, here it is:

https://drive.google.com/file/d/1BCAM5_s0RmaW27qQg1YpBhEUSYFM4KYi/view?usp=sharing

You are fast to respond! Wow.

Ok I pushed a fix

Well, color me impressed, that was fast! It works. Thank You very much.