I am using Cakewalk with my US2X2 in a Windows 10 Pro/64-bit environment. I've had this happen several times and I think it has to do with the seemingly lesser-quality and problematic drivers of the US2X2. I have my song project completely done with drum track and everything (using Steven Slate SSD5 in this case), and all of the sudden with no warning whatsoever I lose the audio from the drum synth track. No changes at all in the track routing, signal flow or other settings. Just working along, and poof no sound from the drums. The track is not muted and has not been altered in anyway. Changing audio mode does not help - ASIO, WASAPI, and MME all do the same thing - nothing. Creating a new soft synth track instance of the SSD5 in the same project does not help either - no sound from it Has anyone had this happen with MIDI synth tracks and the US2X2? My only solution thus far has been to create a brand new blank project, cut each track out of the old project and into the new (with an instance of the SSD5 synth, etc). This is a process that I don't want to have to go through each time this happens. I would like to get to the bottom of why this is happening. It something with the audio drivers I'm pretty sure of it. When I go to mixdown the project to MP3 or WAV the drum audio is missing and silent there as well. The track has MIDI data in it and is routed to the synth and output bus correctly.