First-you guys have been a TON of help and have gotten me this far but it appears that I've run into a real snag. I'm building a DJI F550 with Naza M V2, GPS, Zenmuse H3 2D and Spektrum AR8000 / DX9 combo. I've set everything up according to the directions (and most user's parameters) but when I get to calibrating the TX in the setup assistant, the controller will not calibrate. I've downloaded all the latest drivers (re-installed multiple times to make sure that's not the issue), am running the latest version of Naza Assistant (V2.20), have the latest firmware on the PMU, have re-bound my TX 5 times...but can't seem to get the calibration to recognize the controller. When I try to calibrate it, the sliders are red and don't respond to any of the inputs from the TX (but are moving around sporadically). I've got the wiring from the receiver set up so that Aileron, Rudder, Throttle, Gear and Elevator are in the corresponding A, E T, R and U inputs on the Naza and have also tried quite a few different configurations there. I've also started over with a new model in the TX several times and tried everything from just a plain "Acro" setup with nothing modified to importing a DX9 setup file from another user. The assistant DOES recognize the Naza M via USB as I can check the rotation direction of the motors and it can see the orientation of the gyro + GPS tracking. Lastly, the Naza assistant is giving me a "CFG-ERR" message and asking me to re-calibrate my transmitter (which ironically, I can't). Not sure if my Naza M is just defective at this point but thought I would ask for your suggestions in case there's something I can try that I haven't already. Apologies for the long-winded first post but in desperation mode. Thanks in advance.