The mod Call a Plumber (0.3.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event call-plumber::on_tick (ID 0)
call-plumber/scripts/scanner.lua:92: table index is nil
stack traceback:
call-plumber/scripts/scanner.lua:92: in function 'register_new_cooldown'
call-plumber/scripts/scanner.lua:133: in function 'handle_incompatible_fluid_entity'
call-plumber/scripts/scanner.lua:168: in function 'scan_entity'
call-plumber/scripts/scanner.lua:200: in function 'scan'
call-plumber/control.lua:115: in function <call-plumber/control.lua:114>

looking at the pipelines that I have in my save... It seems like the error appears when a pump It's gonna receive damage (In this case, a pump that tried to move lava)

Thanks for the bug report. I reproduced the crash and it is fixed in the new release. The mod needed to handle pumps differently because the game engine doesn't merge a pump's fluid storage with neighboring pipes.