The mod Companion Drones 2.0 (2.0.10) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event companion-drones::on_pre_build (ID 9)
LuaItemStack doesn't contain key contents.
stack traceback:
[C]: in function 'index'
__companion-drones/script/companion.lua:1562: in function <companion-drones/script/companion.lua:1550>
(...tail calls...)
companion-drones/script/companion.lua:1591: in function 'get_blueprint_area'
companion-drones/script/companion.lua:1625: in function 'handler'
core/lualib/event_handler.lua:47: in function <core/lualib/event_handler.lua:45>

Game version 2.0.20
Mods: Only Space Age and Companion Drones
Blueprint used: https://github.com/bcwhite-code/brians-blueprints/releases/tag/brians-trains

I was placing a blueprint from a blueprint book when this crash occurred. If I disable drones on paste, everything is fine.
Also, if I extract the blueprint to the panel as a separate item, it pastes correctly.

Edit:
Disabled DLC, left just companion drones, crash still happened