This fixes the error “Sorry, This File Type Is Not Permitted for Security Reasons”.

In wp-config.php add this:

define('ALLOW_UNFILTERED_UPLOADS', true);

If you are not using some custome theme but a Wordpress builder of some kind, edit the wp-includes/functions.php. Otherwise go to your theme folder functions.php file (wp-content/themes/yourtheme/functions.php. Add this to enable svg upload:

// Allow additional MIME type upload
function my_custom_mime_types( $mimes ) {
 
// New allowed mime types.
$mimes['svg'] = 'image/svg+xml';
$mimes['svgz'] = 'image/svg+xml';
 
// Optional. Remove a mime type.
unset( $mimes['exe'] );
 
return $mimes;
}
add_filter( 'upload_mimes', 'my_custom_mime_types' );

• WP 5.7
• PHP 7.3.27-1~deb10u1

• https://www.elegantthemes.com/blog/wordpress/how-to-fix-the-sorry-this-file-type-is-not-permitted-for-security-reasons-error-in-wordpress
• https://neliosoftware.com/blog/how-to-upload-additional-file-types-in-wordpress/