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 ('efaf13ce0f0a8557d7a1dfaa58b4a4fa', -1, 1438385069, 1438385069, '365be3e3', -1, 0)

Line : 158
File : sessions.php