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 ('581a2895f1a08a0353b3d5a6452a5009', -1, 1711647972, 1711647972, '2ccc1852', -1, 0, 0)

Line : 187
File : sessions.php