So I just upgraded our wordpress mu 2.92 installation to 3.0. Everything went well until I tried to add a category to Post or Links.
When I try to add the category via single post method I get the following error.
"Fatal error: Cannot use object of type WP_Error as array in C:\wamp\www\wp-admin\admin-ajax.php on line 242"
When I try to add it via Categories or Link Categories I get the following error.
"Could not insert term into the database"
Can someone please help with this. I even disabled all plugins to get this to work but it did not fix the issue.