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 source FROM {url_alias} WHERE alias = :alias AND language IN (:language, :language_none) ORDER BY language DESC, pid DESC; Array
(
    [:alias] =&amp;gt; node/177
    [:language] =&amp;gt; zh-hant
    [:language_none] =&amp;gt; und
)
 in drupal_lookup_path() (line 173 of /srv/www/htdocs/includes/path.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 /><h1>Uncaught exception thrown in shutdown function.</h1><p>PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT rid, permission FROM {role_permission} WHERE rid IN (:fetch_0); Array
(
    [:fetch_0] =&amp;gt; 1
)
 in user_role_permissions() (line 768 of /srv/www/htdocs/modules/user/user.module).</p><hr />