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 ('0ad66a2712be2cff2ee03f3af6358513', -1, 1411344491, 1411344491, '36ea3b5e', 0, 0)

Line : 158
File : sessions.php