phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 2

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in) VALUES ('6362e28e41000bf0df94b0eab92c24bf', -1, 1406183094, 1406183094, '365bbf30', 11, 0)

Line : 315
File : sessions.php