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 ('f7f2e18eb5a7727c5ea0f579f2ea38a4', -1, 1711696900, 1711696900, '2cc8201f', -10, 0, 0)

Line : 187
File : sessions.php