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 ('51abf4017be0545d5f0989ff456c3942', -1, 1711712555, 1711712555, '2cc8bf92', 6, 0, 0)

Line : 187
File : sessions.php