The Cakewalk audio scanner really needed an update no doubt. Try using the CWAF tool instead.
FWIW, The Clean Audio folder works well for me. its takes a long time to do an initial scan (the first one) but if you keep sonar open and scan new projects it will be quicker the second time around because excluded disk folders are remembered in Memory only. this is a downfall.
If the scanner is waiting, don't keep clicking on it either. that will surely cause a crash because there is too much going on as scanning takes up huge amounts of Disk activity. Let the scanner do its job and wait. Sometimes it takes as long as 5 minutes for the first scan to complete.