Yes, it is the MIDI real-time Harmonizer version 3 of Johan Looijenga. It is no plugin; you must open it as standalone Bob, I contacted Mr. Looijenga because I also thought, it could be the harmonizer causing the problem. But he said no and was astonished. Yes, I have Asio drivers, but I have to repeat: For a long time, all worked. But I do not know what caused THAT it worked (In the beginning I had the same problem). And I do not know what caused that it does not work anymore now. In the harmonizer, I changed nothing. So, there have to be a problem in Sonar.