Breaks with update to WP 3.5

Pasting the contents of that file in a gist would help.

p2p-outline-classes_to_events.php

Oh, ok. Please add the p2p_register_connection_type() call to that gist as well (separate file).

Here you go

Ok, could you explain what you mean by “The connected class no longer displays, rather it displays itself.”

Also, if you replace the ‘event’ post type in the connection type with ‘page’, for example, does it work as expected? (I’m trying to get the Event Manager plugin out of the picture).

On this dev version of the site, where you see the link ‘View Class Outline’ which linked to the class overview CPT, you can see that it now just links to the current page (itself). If I roll back to 3.4 it works again.

I’m happy to provide you ftp/wp access if you want to take a closer look.