Original

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 = 'default'; Array ( [:language] => ru [:source] => Configure how content input by users is filtered, including allowed HTML tags. Also allows enabling of module-provided filters. [:context] => ) in locale() (line 720 of C:\xampp\htdocs\drupal\modules\locale\locale.module).

Additional

PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT lid, location FROM {locales_source} WHERE source = :source AND context = :context AND textgroup = 'default'; Array ( [:source] => An AJAX HTTP error occurred. [:context] => ) in _locale_parse_js_file() (line 1563 of C:\xampp\htdocs\drupal\includes\locale.inc).

Uncaught exception thrown in session handler.

PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away in _drupal_session_write() (line 209 of C:\xampp\htdocs\drupal\includes\session.inc).

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY000]: General error: 2006 MySQL server has gone away' in C:\xampp\htdocs\drupal\includes\database\database.inc:2168 Stack trace: #0 C:\xampp\htdocs\drupal\includes\database\database.inc(2168): PDOStatement->execute(Array) #1 C:\xampp\htdocs\drupal\includes\database\database.inc(680): DatabaseStatementBase->execute(Array, Array) #2 C:\xampp\htdocs\drupal\includes\database\database.inc(2347): DatabaseConnection->query('SELECT expire, ...', Array, Array) #3 C:\xampp\htdocs\drupal\includes\lock.inc(167): db_query('SELECT expire, ...', Array) #4 C:\xampp\htdocs\drupal\includes\lock.inc(146): lock_may_be_available('schema:runtime:...') #5 C:\xampp\htdocs\drupal\includes\bootstrap.inc(424): lock_acquire('schema:runtime:...') #6 C:\xampp\htdocs\drupal\includes\bootstrap.inc(446): DrupalCacheArray->set(Array) #7 [internal function]: DrupalCacheArray->__destruct() #8 {main} thrown in C:\xampp\htdocs\drupal\includes\database\database.inc on line 2168