2013 - Lost connection to MySQL server during query

SELECT content_id, categories_id, parent_id, content_title, content_group FROM content_manager WHERE languages_id='2' and file_flag=1 and content_status=1 order by sort_order

[XT SQL Error]

2006 - MySQL server has gone away

select count(*) as total from sessions where sesskey = '8mvltcni9bv29k9jh688hvns12'

[XT SQL Error]