phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO start_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in) VALUES ('1aad0f4b2733d85589464c95b8a5daf3', -1, 1409613793, 1409613793, '36a6539a', -1, 0)

Line : 158
File : sessions.php