phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'c5516b3191b80b687ea361b51ab80250' for key 'PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('c5516b3191b80b687ea361b51ab80250', -1, 1406336705, 1406336705, '36ed4db5', -1, 0, 0)

Line : 187
File : sessions.php