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 ('f35767b1d04961a0af49b3719af6e708', -1, 1711646771, 1711646771, '12ccd6cd', 0, 0, 0)

Line : 187
File : sessions.php