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 ('85ea4233cc68db9944bfc03509175995', -1, 1416845479, 1416845479, '36ea0055', -1, 0, 0)

Line : 187
File : sessions.php