Fatal error: Call to undefined function wp_register_sidebar_widget() in /blog/wp-admin/includes/dashboard.php on line 31

3/31/2008 by Elliot Lee | Filed in Technical | No comments

WordPress 2.5 is not compatible with older versions of K2. You’ll know if you have this problem because this error message appears:

Fatal error: Call to undefined function wp_register_sidebar_widget() in /blog/wp-admin/includes/dashboard.php on line 31

I had this problem, and found a solution in the WordPress Forums. I wonder why it happens and how the K2 people fixed it.