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 fc.*
FROM 
{field_config} fc
WHERE  (fc.active = :db_condition_placeholder_0) AND (fc.storage_active = :db_condition_placeholder_1) ; Array
(
    [:db_condition_placeholder_0] => 1
    [:db_condition_placeholder_1] => 1
)
 in field_read_fields() (line 372 of /mnt/panlin/modules/field/field.crud.inc).</p><h2>Additional</h2><p>PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT fc.*
FROM 
{field_config} fc
WHERE  (fc.active = :db_condition_placeholder_0) AND (fc.storage_active = :db_condition_placeholder_1) ; Array
(
    [:db_condition_placeholder_0] => 1
    [:db_condition_placeholder_1] => 1
)
 in field_read_fields() (line 372 of /mnt/panlin/modules/field/field.crud.inc).</p><hr />