I just updated from WP3.1 to WP3.2 and it immediately crashed my site.  A hard crash, no admin panel, nor error message. Fortunately I did this at the Automattic office, so I had the core guys there to help me.

Now here is a tip, if your site ever locks up after installing a plugin or an upgrade, FTP into your site and change this directory

/wp-content/plugins  to  /wp-content/plugins_foo

If that does not work, then change this directory;

/wp-content/themes/{the name of your current theme}/ -> /{theme}_foo

This should put your site back to the default design which will at least get you up and running again till you can figure out what went wrong.

Now in my case, I’m using the arras theme.  It crashed because a widget that the theme overrides, tag-cloud, is now deprecated. There may be many other themes that are doing the same thing.  You can tell by looking at the error logs.

Here is what you need to change on line 404 of the file widgets.php (you can find this file in /themes/arras/library):

Change this line -> $this->WP_Widget_Tag_Cloud();

To this line -> parent::__construct();

The new class call should read as the following…

class Arras_Widget_Tag_Cloud extends WP_Widget_Tag_Cloud {
function Arras_Widget_Tag_Cloud() {
parent::__construct();
}

There is a list of widget that have been deprecated.  If your wordpress is hard crashing, its possible that your theme could be using one of these widgets.  Simply find where this is called in your theme and replace the call as I showed above.  Hopefully this will fix it.

Good luck!

$_wp_deprecated_widgets_callbacks = array(
‘wp_widget_pages’,
‘wp_widget_pages_control’,
‘wp_widget_calendar’,
‘wp_widget_calendar_control’,
‘wp_widget_archives’,
‘wp_widget_archives_control’,
‘wp_widget_links’,
‘wp_widget_meta’,
‘wp_widget_meta_control’,
‘wp_widget_search’,
‘wp_widget_recent_entries’,
‘wp_widget_recent_entries_control’,
‘wp_widget_tag_cloud’,
‘wp_widget_tag_cloud_control’,
‘wp_widget_categories’,
‘wp_widget_categories_control’,
‘wp_widget_text’,
‘wp_widget_text_control’,
‘wp_widget_rss’,
‘wp_widget_rss_control’,
‘wp_widget_recent_comments’,
‘wp_widget_recent_comments_control’
);