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 ('99b48e3eb033e75e0f7340837c46c4ca', -1, 1711710884, 1711710884, '22ef96f7', -4, 0, 0)

Line : 187
File : sessions.php