Sorry, this file type is not permitted for security reasons

If you come across the error when uploading files: “Sorry, this file type is not permitted for security reasons”, to overcome this security measure put in place by WordPress add the following code to your themes functions file.

function iwp_example_allow_xml_uploads($mime_types)
{
    $mime_types['xml'] = 'text/xml';
    $mime_types['json'] = 'application/json';
    $mime_types['csv'] = 'text/csv';

    return $mime_types;
}
add_filter('upload_mimes', 'iwp_example_allow_xml_uploads', 1);

Allow unfiltered uploads in your wp-config.php file

To allow all the uploading of all file types you can add the following line of code to your wordpress config file wp-config.php, this will bypass the secuirty of wordpress and unrestrict what files can be uploaded, (i would recommend removing this after you have uploaded your file).

define('ALLOW_UNFILTERED_UPLOADS', true);