Block XML on main directory, unblock in an app directory.

[Mendex]

That worked!

For reference, the htaccess File that worked:
-----------------------------------------------------------------------
AddDefaultCharset UTF-8
Options -Indexes

RewriteEngine on

# Usually it RewriteBase is just '/', but
# replace it with your subdirectory path
RewriteBase /

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule /?([A-Za-z0-9_-]+)/?$ index.php?id=$1 [QSA,L]
---------------------------------------------------------------------

Big thanks Shawn and Carlos for your time an patience.

Best Regards,

Mendex