2011 CTS with Nav and Bose. Recently when I plug in a USB drive with some MP3 files on it, the system shows AUX and Searching and then a window pops up with 'This USB is not supported. Disconnect the device.' I tried formatting the USB drive and putting just one MP3 file on it but I got the same result. I have successfully done exactly this operation in the past and I could both play the files and record them to the HDD! Any suggestions?