phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO phpbb2_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('64b691a32cd9a66cb7b295d8648e8c2e', -1, 1596730610, 1596730610, '03eb6bd1', 0, 0, 0)

Line : 187
File : sessions.php