Hi, Rounik I tried both suggestions; here's what happened. The bus creation and instanciation process, and track soloing worked flawlessly in a different project from the one I'd been having trouble with. I tried removing the preference from the User/library folder and found that I was still having the bus creation/soloing problem with the trouble project. This suggests 2 things: -There is probably not a problem with Logic itself -either the problem project is somehow corrupted, or has confused Logic, or has a setting causing problems that I'm not aware of. Or...?

Thanks, Rounik- I just sent a message to your attention via the Support area. cheers Dex

Hi, Rounik Yippeee! It worked! Good news indeed! Thank you so much-you are a gentleman, a scholar and so kind to check my file. I agree-much good has come of this in that others will benefit from this learning. with much appreciation Dex