Hi Andrew, strange and confusing results...any ideas as to what is causing P3Dv5 to crash? Could you try the following dll please (6.0.3d): FSUIPC6.dll It has additional logging. Start with only the following in your ini:     Debug=Please     LogExtras=1 Just before you close the session, go into the logging tab and set the extras value to 8197. If you could then generate a log when iy hangs. Thanks, John