xdj rx - 8307 error

Hi, firstly love the unit but after having the lads round a few week back for a session I noticed that when they loaded their android phones into the unit that we got the error 8307 msg, now I used the usb cable that comes with my HTC one m8, I don't know whether the issue is with the cables transfer format or not. I've not seen any specific post regarding this problem and also waited till the 1.70 firmware update to see if this matter was resolved but obviously it hasn't... Cheers