I Have just updated and reverted back to 4.2.1 after experiencing weird bugs and errors. The track would suddenly change to another track or just loads of white noise on top. I have a video showing what happens just need to upload it if anyone wants it. But now its fine. I connect through LAN to my pc running rekordbox. I got scared for a bit an thought it was the decks as i just got them two days ago.. oooooof