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 ('927d2bd967b48033b778ccc6fb79e70a', -1, 1409648843, 1409648843, '365242ec', 33, 0)

Line : 315
File : sessions.php