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 ('87bb86c408e943d699b22e2d4e2d6522', -1, 1711716334, 1711716334, '2ccad169', -7, 0, 0)

Line : 187
File : sessions.php