After upgrading to wpmu 1.2.1, posts, pages and categories links not working on some blogs. Also when I try to post on those blogs, it returns 500 error.
When I try to access posts, pages or categories on those blogs, it gives following warning in the header:
Warning: Invalid argument supplied for foreach() in /home/myusername/public_html/wp-includes/classes.php on line 88
Line 88 of wp-includes/classes.php is this:
foreach ($rewrite as $match => $query) {
What might cause this? Thank you in advance.