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 ('5e6168a0f55c54b6a2f046249c27ca09', -1, 1490228291, 1490228291, '369eb7bc', 12, 0, 0)

Line : 187
File : sessions.php