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 ('1ba5106409813dfae5f62dbce6c0fb1d', -1, 1397901967, 1397901967, '36c624b3', 3, 0)

Line : 158
File : sessions.php