Although Front-end Editor tries to be compatible with as many themes as possible, there’s only so much it can do.

Lots of plugins, including this one, rely on the wp_footer() call to include their JavaScript files. Open your theme’s footer.php file and make sure you have this line somewhere:

<?php wp_footer(); ?>

Using custom versions of jQuery

Some themes, for one reason or another, use their own jQuery file. When a new version of WordPress is launched, the bundled jQuery library is also updated, but the theme is stuck using it’s own, outdated version.

View the HTML source and make sure the path to jQuery looks like this: wp-includes/js/jquery/jquery.js.

Using the_title() in the wrong places

A mistake I see in a lot of themes is code like this:

<a title="Permanent Link to <?php the_title(); ?>" href="<?php the_permalink() ?>"><?php the_title(); ?></a>

This causes all sorts of problems. You should use the_title_attribute() instead:

<a title="Permanent Link to <?php the_title_attribute(); ?>" href="<?php the_permalink() ?>"><?php the_title(); ?></a>

No id & class attributes for dynamic sidebars

If you want to have editable widgets, you’ll have to change code like this:

register_sidebar(array('name' => 'My Sidebar',
	'before_widget' => '',
	'after_widget' => '',
	'before_title' => '<h4>
  ',
  	'after_title' => '
</h4>',
));

to this:

register_sidebar(array('name' => 'My Sidebar',
	'before_widget' => '<div id="%1$s" class="widget %2$s">
  ',
  	'after_widget' => '
</div>',
	'before_title' => '

<h4>
  ',
  	'after_title' => '
</h4>',
));

The important part is id="%1$s" class="widget %2$s".