I'm running into a new thing on Export. (other settings ="Entire Mix, Stereo, 44.1, 32 bit and "All")
This one song has two items listed in the source/busses/tracks.
1.-"None" and
2.-"BR800" (my sound card/interface)
The "none" is new and is it connected with the results being fairly quiet as opposed to the usual almost maximised wave form?
I went back to other songs but they only had BR800 shown.
I thought it should say "Master" but maybe it never did.

The --None-- in Buses and Tracks would indicate some of the tracks and/or buses have --None-- selected at their output.

That's what the song startup alert says too.
"Guitar and vox busses assigned to silent hardware."
But I have checked and double checked outputs. (It is just about the outputs right?)
All the tracks are output to proper busses and all busses are output to Master and master to the BR800.
I have learned to ignore the startup alerts as almost never being right.

It appears that once the "silent hardware" condition occurs in a project, the error flag is set and is never reset. I know of no way to manually reset the error flag in the project. There is a way to suppress the error message from ever popping up. To suppress the error message set WarnSilentBuses to 0 (zero) in Edit > Preferences > File > Initialization File. As with all advanced settings make sure the Advanced radio button is selected at the bottom of the Preferences dialog to see the Initialization File option.

Re  Edit > Preferences > File > Initialization File.
What does it mean if the boxes are all blank in this one?

It means that you have never ventured into this area. It is blank by default. You add option/value pairs with the entry widgets, then click the Set button. In this case option would be WarnSilentBuses and value would be 0.

Lol True.
Ok I'll bite..
What's an entry widget?

A screen object used for data entry like the Option and Value items on the Initialization File pane in preferences dialog

Is this a function of Sonar?

I was trying to describe how to enter values in the Initialization File area of the Preference screen that is all.