Delete unused busses?

[dg27]

I always repurpose sessions (i.e., use old sessions as a template).

I was finishing a session last night and got an error message that I had run out of busses, which I founds very weird. I never use the default numbered busses: I always create buses for specific purposes, named accordingly, e.g., "voc verb."

I went into the I/O setup and saw a long list of busses I was not using in this session, but had used in the past.

Is there any way of getting rid of those I don't need?

I've searched regarding this to no avail.

[64GTOBOY]

In I/O setup, busses, highlight and click delete button for each unused buss

[dg27]

Thank you, 64GTOboy. This was driving me slightly mad, though I should have been able to figure it out.