What a mess! I succeeded the mission but had so many problems so I cannot write them all here. I couldn’t reach the required altitude and the plane was so slow so that I did a shortcut compared to the flight plan. I landed but there was no hold short box so I pressed Alt+N and then suddenly I was in the air again at 25000 feet 
! Ok, I tried again and could land but I never got the taxi clearance so I pressed Alt-N again and mission succeeded but after four hours of struggling I only got 5000 Cr. I think I’ll leave this career stuff for now until they have fixed all the crazy bugs which are all over the place.