I downloaded RCV 4.2.3831. It works with FS9, but when I open with FSX I am receiving the following warning:"IPC Request contains bad Data"MY downloaded to RCV 4.1 in Program files.Will you please advise.Sanal

I forgot to mention. In FXS I don't have a FSUIPC. Do I need FSUIPC for FSX RCV 4.2.3831.Sanal

Yes, version 4.x. See installation information at the head of these forums.http://www.schiratti.com/dowson.htmlnear the top is where you can get it. RC will register itself.You will need an upgraded installation of RC using 4.3 as well.Look at the install instructions which cover using 4.3 with FS9, FSX, or both.