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 ('0a7060e3f3bc988ccc0b3def8ab4aa57', -1, 1397844678, 1397844678, '36cc431a', 2, 0)

Line : 158
File : sessions.php