phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'c70c919819c02582e03add814dd64720' 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 ('c70c919819c02582e03add814dd64720', -1, 1406813674, 1406813674, '36edf90a', 15, 0, 0)

Line : 245
File : sessions.php