Persistent popup that says silent bus detected is wrong

[Billy86]

One of those PITA things... So, every time I open a project, I get a popup that says a silent bus has been detected. I've had them before, and they're always wrong. In this case, it's telling me my Drum Bus is assigned to a silent hardware output, but it's not. It plays fine.

The drum bus is routed to a submix (it contains everything but vocals), which routes the the master bus and then hardware outputs (Focusrite 4i4).  Simple, no problem. There's not an issue, but I get it every time; no big deal I supposed, but it's one of those nags you don't really need every time you pop open CbB. Why is it doing that, and how do I "fix" it... I say "fix" it because nothing appears to be wrong?

Thanks!