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 ('78845088f5b99a0947ff3b96a2bd9829', -1, 1711713875, 1711713875, '365c9b5d', -4, 0, 0)

Line : 187
File : sessions.php