Hi there folks, Sorry, I posted this in the wrong forum. I will go and delete the other copy after posting this... I'm a Logic Pro user, have been since it was owned by Emagic. I love the program and really enjoy many of the new features that Apple brought the UI. That said, I have been having a problem with songs getting altered mysteriously. It's happened sporadically over the last couple of years. For example, I had been working on a song in May. I left the song to gestate, and went back yesterday to add another voice to it. Opened the song: the sound sounded fine. Added a track. All of a sudden not only is the mix completely bizarre, but two of my exs-24 midi instruments have been blanked and are just sine-waves. All of this has happened before (although sometimes it's just opening the song and finding that it has been mysteriously deranged) and I can't for the life of me figure out what is causing it. It's EXTREMELY frustrating to have a mix suddenly deranged by the software. So much work goes in to get things just right. Really they will never be exactly the same. The only 3d party plugins I use are Abbey Road Brilliance Pack, Trillian and Augustus Looper. Everything else is native Logic Pro. Does anyone know anything about this terrible bug and what I can do about it?