Situation:
- Use a nixie tube to display a custom signal from another mod.
- Remove that mod and load the save.
- Custom signal is not there anymore, nixie tube mod crashes

Error message:
The mod Nixie Tubes (2.0.1) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event nixie-tubes::on_tick (ID 0)
value for required field 'name' is missing
stack traceback:
[C]: in function 'get_signal'
nixie-tubes/control.lua:327: in function 'onTickController'
nixie-tubes/control.lua:410: in function <nixie-tubes/control.lua:396>

Workaround:
- remove all nixie tubes with custom signals before removing the other mods