Hi!
I found a more hackier solution that fixed it for me before I read the whole thread.
I directly edited the taconomy.php
In lines 11 to 13 I took out the (object)
casts.
$wp_taxonomies['category'] = array(...);
$wp_taxonomies['post_tag'] = array(...);
$wp_taxonomies['link_category'] = array(...);
And in the function get_taxonomy( $taxonomy )
I added the (object)
cast again in line 68:
return (object)$wp_taxonomies[$taxonomy];
So far I didn’t notice any errors. But I didn’t test every part of wordpress after changing. So use with caution!