mortal valley
I try to build and flash my R9MX receiver to version 3.2 but I get Unable to connect to the MCU device error. I noticed that the receiver has no light once I install no button boot loader in it through ST link utility. Not sure why? I do have another receiver R9 slim plus it’s build and flash just fine. Strange? I know the receiver supposed have red light blinking when unplug ST link but there is no light on receiver when unplug.
placid storm
I try to build and flash my R9MX receiver to version 3.2 but I get Unable to con...
have you already used STLink Utility to disable Read out Protection?
How new is this R9MX?
mortal valley
Thank you so much sir, deadbyte. 
Your advice solves the flash problems. PIO STLink solution works perfectly. After copy the files to the folder as provided in the instructions, I am able to flash the receiver now. You are the best. by the way I checked that there is no write protect and the R9MX was purchased online last month. Also I saw your YouTube expresses testing before. Just subscribed.