phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 'session_user_id'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('dda7c7d2c2481d4c8c81f6768e19952f', -1, 1569051902, 1569051902, '23afbf96', -9, 0, 0)

Line : 187
File : sessions.php