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 ('33b978d5d4fe095ea8bec2f073bbf312', -1, 1409648838, 1409648838, '365242ec', 32, 0)

Line : 315
File : sessions.php