(EDIT!! Nvm, only saw your reply from another forum 10 mins after this.)
(Edit 2: After tweaking Nicefill to see the bots true abilities, they are freaking amazing. A bit cheaty imo, but wonderful, thank you Klonan. I barely keep a handful of core mods to use from game to game in Factorio, but this is now one of them.

Everything seemed fine until I used the drones to place stone brick. (informing the other modder too)

The mod Construction Drones (0.5.2) caused a non-recoverable error.

Error while running event Construction_Drones::on_ai_command_completed (ID 113)
The mod NiceFill (0.1.17) caused a non-recoverable error.

Error while running event nicefill::on_robot_built_tile (ID 47)
nicefill/control.lua:312: attempt to index field 'robot' (a nil value)
stack traceback:
nicefill/control.lua:312: in function <nicefill/control.lua:298>
stack traceback:
Construction_Drones/script/construction_drone.lua:2193: in function <Construction_Drones/script/construction_drone.lua:2138>
(...tail calls...)
core/lualib/event_handler.lua:44: in function <core/lualib/event_handler.lua:42>
stack traceback:
[C]: in function 'raise_event'
Construction_Drones/script/construction_drone.lua:2193: in function <Construction_Drones/script/construction_drone.lua:2138>
(...tail calls...)
core/lualib/event_handler.lua:44: in function <core/lualib/event_handler.lua:42>