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 ('b3f06a7a5a18bee9732cd732ce6e7f90', -1, 1513503867, 1513503867, '6b147841', 0, 0)

Line : 158
File : /Forums/includes/sessions.php