I’ve the same problem on subdomains. In my case it’s a multisite setup. Some subsites use domain mapping, they are on a own domain and it works. But the subsites without domain mapping, that are on a subdomain, show a 404 on the events detail page. The listing on the events page, location page and bookings page work well, the error is only on the details page.

I used the script debug, so the customize-controls.js was used by WP. Did you already used the body tag instead of html in the customize-controls.min.js, too? That’s usually used by WP. Thanks! So let’s keep on fighting 😉

Hi Davey, please look at the mentioned ticket, I posted my solution there. You can try this until the next version is coming out.

in class-wp-customize-manager.php the scripts are not enqueued.
if I comment out this function (#684) or the belonging action hook
add_action( 'customize_controls_enqueue_scripts', array( $this, 'enqueue_control_scripts' ) );
on my running local install, the result is completely the same as on remote (empty div, missing scripts):

public function enqueue_control_scripts() {
		foreach ( $this->controls as $control ) {
			$control->enqueue();
		}
	}

I haven’t seen this way of enqueuing in WordPress before. And it doesn’t make sense why this should be differently handled by servers.
I think I’ll open a ticket maybe.

same problem here.
Interesting: it works on my local server but not on the remote live site. Files and database dump are completely the same (except server path and tld of domains). There are php errors on the domain mapped subsites, but not on the main site (and there the customizer doesn’t work, too, on remote server).

Didn’t want to reinstall yet, because I’ve a running multisite network. But I tried reuploading the WordPress core files (and deleting old ones first) from current version 3.4.2, I did a database dump switch to a new database. and of course first deactivating all plugins, switching between integrated (Twenty Eleven) and own themes. didn’t help.