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 ('c6df3182689a705e77f045ac06ef1df8', -1, 1711679869, 1711679869, '2cd42795', -4, 0, 0)

Line : 187
File : sessions.php