I did a test with all plug ins disabled.
Created a new BLANK project and saved it. ON creating it, three wav files were produced.
If I added any tracks, the number of wav files increased significantly.
The only way to access any of these is if Sonar crashes. When I preview any of the ones left aftger the creash, there is nothing in them - or at least nothing is audible, but I can't insert them into a new project audio track - nothing happens if I try.
I even tried using an different audio output, disabling all inputs. No change.
I'm completely at a loss now.
I can still work on projects, but it takes such a long time to add tracks, delete tracks, move tracks - and not a single audio track in the projects.