phpBB : Erro Crítico

Error doing DB query userdata row fetch

DEBUG MODE

SQL Error : 2013 Lost connection to MySQL server during query

SELECT u.*, s.* FROM f_activesessions s, f_activeusers u WHERE s.session_id = '869305319bb8715bcf976159620e8936' AND u.user_id = s.session_user_id

Line : 315
File : sessions.php