Custom menu stuck

All of a sudden my custom menu get stuck and just shows the loading icon when trying to add new menu items. There’s a bunch of items already, but i’ve done menus before with a whole lot more.

If I hit the ‘Save’ menu button it gives me the white screen of death which made me check my functions.php, and nothing looks wierd.

<?php
add_action( 'init', 'my_custom_menus' );
function my_custom_menus() {
    register_nav_menus(
        array(
            'primary-menu' => __( 'Primary Menu' ),
            'secondary-menu' => __( 'Secondary Menu' )
        )
    );
}
register_sidebar(array(
	'name' => 'Right sidebar',
	'description' => 'Links.',
	'before_title' => '<div style="display:none;">',
	'after_title' => '</div>',
	'before_widget' => '<div id="%1$s" class="widget %2$s"><li>',
	'after_widget' => '</li></div>'
	));
	 register_sidebar(array(
	'name' => 'Left sidebar',
	'description' => 'Links.',
	'before_title' => '<div style="display:none;">',
	'after_title' => '</div>',
	'before_widget' => '<div id="%1$s" class="widget %2$s"><li>',
	'after_widget' => '</li></div>'
	)); ?>

Made sure all the white space was gone, but i’m still not able to add items to my menu.