Additional uncaught exception thrown while handling exception.

<h1>Additional uncaught exception thrown while handling exception.</h1><h2>Original</h2><p>PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT ml.*, m.*, ml.weight AS link_weight
FROM 
{menu_links} ml
LEFT OUTER JOIN {menu_router} m ON m.path = ml.router_path
WHERE  (ml.link_path IN  (:db_condition_placeholder_0)) AND (language IN  (:db_condition_placeholder_1, :db_condition_placeholder_2)) ; Array
(
    [:db_condition_placeholder_0] =&amp;gt; search
    [:db_condition_placeholder_1] =&amp;gt; zh-hant
    [:db_condition_placeholder_2] =&amp;gt; und
)
 in menu_link_get_preferred() (line 2513 of /srv/www/htdocs/includes/menu.inc).</p><h2>Additional</h2><p>PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT s.lid, t.translation, s.version FROM {locales_source} s LEFT JOIN {locales_target} t ON s.lid = t.lid AND t.language = :language WHERE s.source = :source AND s.context = :context AND s.textgroup = &amp;#039;default&amp;#039;; Array
(
    [:language] =&amp;gt; zh-hant
    [:source] =&amp;gt; WATCHDOG: [@severity] [@type] @message | user: @user | uri: @request_uri | referer: @referer_uri
    [:context] =&amp;gt; 
)
 in locale() (line 720 of /srv/www/htdocs/modules/locale/locale.module).</p><hr />