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 ('b84a15e6deb45e4d269b96e78da03576', -1, 1513225011, 1513225011, '36eaf776', 1, 0)

Line : 158
File : sessions.php