The process with enable GUI is more complicated. Have you started and connected the GUI at all and is it showing the track running on LFS. GUI is not necessary unless you want to manually change camera (which you would really need a second screen for) for broadcasters.
I have insim issues that must be codepage-related. I use LFSrelax and it uses a special character for the fuel calculations namely a fuelpump. Now in Y20 I see ". My guess is that something changed there (might be in Y19 as well...memory leaves me).
Well its pretty much 3 programs in 1 (hence the name).
Pitspotter for warning you about cars getting to close
Teamspeak control
Race position data, Best times/lap data, Fuel warning, virtual speed for cars that have lost it since Y.