The WordPress media library is restricted to certain file types, and vCards are not one of them. Add this code to your theme’s functions.php file or core functionality plugin to allow vCard uploads.
/**
* Enable vCard Upload
*
*/
function be_enable_vcard_upload( $mime_types ){
$mime_types['vcf'] = 'text/vcard';
return $mime_types;
}
add_filter('upload_mimes', 'be_enable_vcard_upload' );