You might experience that earlier completed missions, parking ticket etc. are still not unlocked. Please check that the version of FSc is at least v1.0.8868 (bottom line in the opening screen)
To unlock your parking ticket let ATC help you and activate progressive taxi way. This will point you to a parking stand. Set parking brakes. Done.
Flight of the Navigator
However all missions have been completed (7.250 point) the achievement is still locked.
To unlock the achievement fly once one of the earlier completed missions to unlock.
The issues are solved with update 6.