What the *%$# !
I'm getting the same error. I am not using a RealFlight controller or adapter. I am using a serial port controller made from an old transmitter. It works fine with Dave Brown RCFS, FMS, and every other simulator that I have tried. So, why is it so difficult for RealFlight to recognize the controller when it is readily available through the system? According to the documentation, RealFlight will recognize serail port systems. I have never had another software package that was so difficult to install and get it operating. This from a $200 software package.