Originally Posted by mbovenka
No. I have more (about 59K) and I have run a successful binary compare recently, so it's not the number of books as such. Perhaps running Calibre in debug mode and trying it again will give some useful info?
Agreed - I'm at just about 79k, and while binary compare takes a long time, it does run. I use a scheduled script to move files into my auto-import folder, I need to disable that anytime I run a bigger search (like this), prevents unexpected use of resources during the search...