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 ('f16fbe1eee35917f468d87058599234e', -1, 1711694699, 1711694699, '2cc831c1', 6, 0, 0)

Line : 187
File : sessions.php