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, session_admin) VALUES ('a32d3eeae9d2919c5f570f9f5b0ee412', -1, 1369305543, 1369305543, '17164caa', -1, 0, 0)

Line : 187
File : sessions.php