Note: This bug report was posted in Portuguese sub-forum by playrp.
All my airports have one landing lane per line. And all aiports on this game can load pax and mail.
The bug happens when the mail planes keep waiting to fill 100% and sometimes need to wait for a free lane. But they don't go to one, they keep stuck on the taxiway exit. And even sending it to the depot don't work.
So I sent all planes to the depot, created a new landing lane on all airports and released them all. The jam persisted and Simutrans crashed.
Running on Windows 7, with compatibility mode with windows 7 and admin mode.
Planes ignore oneway signs for route search with waypoints. Known bug, but cause not yet found.