I just used "automatic upgrade" to take me to v2,0 of YARPP and now it's failing to work. The admin page comes up fine, but I get either "no matching results" or a PHP error (see below) depending on the options I select within Titles/Bodies/Tags/Categories. If I select any of them to any degree, I get simply "No related posts." I've tried dropping the relevance from 3 (where it worked before) to 0.1!
If I set all four to "Do not consider", I get the following error again followed by "No related posts.":
Warning: Division by zero in /homepages/8/d151455252/htdocs/Moshtour/wordpress/wp-content/plugins/yet-another-related-posts-plugin/magic.php on line 85
Either way, no joy - a shame as the previous version was great!