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 ('3d7ec066ad049735ca82b5392c6b038f', -1, 1490249235, 1490249235, '36d3a94c', -4, 0, 0)

Line : 187
File : sessions.php