try also unsubscribe / subscribe the airline

That is strange , but for that you need help by the developers ofs sa , because also if the mod would not work , you would see a UFO plane. So that looks like a game problem. So please send in a bug report to the devs

Strange. I accepted the contracts, set the gates, etc. NO planes ever landed. All other airlines behave just fine. After a few weeks, and 25 contracted, scheduled flights, thousands of people waiting, none of these planes show up.