My .htaccess fiel in the same folder of the chat.html file show only thsi code for now:
RewriteEngine On
RewriteCond %{ENV:SECURE_REDIRECT} !=on
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
then I added this line:
AddType text/plain .rive
and nothing changed.
And after renaming all files from .rive to .txt was back all right, hurrah!
Big Thanks a lot Noah !