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 ('83de1cde2efa66abe9ab9fc43ae80888', -1, 1506197347, 1506197347, '36e09ee8', -8, 0, 0)

Line : 187
File : sessions.php