When typing anything or pasting any text, this error message appears. I'm in the sandbox mode with cheat mode enabled.

The mod MicroController (0.7.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event m-microcontroller::on_gui_text_changed (ID 2)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
m-microcontroller/stdlib/entity/entity.lua:52: in function 'get_data'
m-microcontroller/microcontroller.lua:61: in function 'update_program_text'
m-microcontroller/control.lua:139: in function <m-microcontroller/control.lua:128>
stack traceback:
[C]: in function 'index'
__m-microcontroller/stdlib/entity/entity.lua:52: in function 'get_data'
m-microcontroller/microcontroller.lua:61: in function 'update_program_text'
m-microcontroller/control.lua:139: in function <m-microcontroller/control.lua:128>

Aaah, seems last 1-2 updates affect it

Well... you can check previous versions. I want a day off tomorrow...

Thank you for an instant reply. I tested previous two versions 0.7.1 and 0.7.2 and both didn't work.

BTW, I framed the problem wrongly. This error occurred when I tried to type into another combinator, fCPU's programmable combinator by extermeon. Might it be these two mods modify some same entities?

Might it be these two mods modify some same entities?

Probably not although it can be a thing as a GUI's interference...