I alerted mitcho to this problem yesterday in Twitter, but it seemed wise to document it here too, both for his sake & for the sake of other YARPP users.
Here's what I'm getting:
Warning: cannot yet handle MBCS in html_entity_decode()! in /home/henkimaa/public_html/lainen_wp/wp-content/plugins/yet-another-related-posts-plugin/keywords.php on line 7
I've got two WordPress blogs both running on a Bluehost server using PHP 5.2.17. One blog, Henkimaa, was on WordPress 3.1.1 yesterday (I hadn't yet had time to install the update); the other, Bent Alaska, was using WordPress 3.1.2. For both blogs, everything had been working fine up until yesterday, when suddenly the problem occurred, forcing me to disable YARPP on both blogs. (I've since updated Henkimaa to WP 3.1.2.)
It's pretty bizarre that this problem just suddenly showed up out of the blue, when YARPP had been functioning quite normally with both blogs up until that time.
YARPP is a great plugin, & I am assuming this is a very temporary problem. Thanks mitcho for already being responsive on Twitter. Hope this further documentation helps us get to the root of the problem. Any help/suggestions welcome.