Here's the long procedure to update / un-update this. First, do the select 2-5 while powering on to change the OS of your mixer, send the 1.04 files (about 6 minutes). Reboot as instructed. Then, select 6 and 9-10 on power-up to update the Difat while the old OS is loaded. Restart when finished. You can check the Difat now- unplugging the lightpipe should make the adat light go out immediately, will turn on when plugged in. If you wish to do diagnostics on the Difat, now is your chance- this feature was removed from the new operating system due to lack of space. When you're ready, update the VM3100pro again, and things should be complete. The MTR button should appear every time.