Daniel

In my completely custom-theme, hand-coded, I removed this code in the functions.php:

/**
 * The TwentyTen Five Caption shortcode.
 * added by Richard Shepherd to include HTML5 goodness
 *
 * The supported attributes for the shortcode are 'id', 'align', 'width', and
 * 'caption'.
 *
 * @since TwentyTen Five 1.0
 */

add_shortcode('wp_caption', 'twentyten_img_caption_shortcode');
add_shortcode('caption', 'twentyten_img_caption_shortcode');

/**
 * Prints HTML with meta information for the current post—date/time and author.
 *
 * @since TwentyTen Five 1.0
 */
function twentyten_img_caption_shortcode($attr, $content = null) {

	extract(shortcode_atts(array(
		'id'	=> '',
		'align'	=> 'alignnone',
		'width'	=> '',
		'caption' => ''
	), $attr));

	if ( 1 > (int) $width || empty($caption) )
		return $content;

if ( $id ) $idtag = 'id="' . esc_attr($id) . '" ';
$align = 'class="' . esc_attr($align) . '" ';

  return '<figure ' . $idtag . $align . 'aria-describedby="figcaption_' . $id . '" style="width: ' . (10 + (int) $width) . 'px">'
  . do_shortcode( $content ) . '<figcaption id="figcaption_' . $id . '">' . $caption . '</figcaption></figure>';
}

.. and now the caption works fine again! Thanks to Andrew Nacin for the right tip!

Thanks for this!! It worked but it take some time, jeah…

If you know how, you can fix the database-stuff at your local installation (MAMP), that’s less stress then a long downtime.

And remember to take care of all settings (also from the plugins) before you take the last step – changing the database! 🙂

Good luck, and maybe there is a better way.