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 ('dad6c5923a782c8e15bbffe1e971f9d4', -1, 1511361219, 1511361219, '36c66c13', 0, 0)

Line : 158
File : sessions.php