Sanitize filename on WordPress upload to not brake links with UTF-8 characters

functions.php

<?php
/**
 * Sanitize filename to not brake links with UTF-8 characters
 *
 * WordPress allow to upload files with names containing UTF-8 characters. Some
 * browsers do not handle properly UTF-8 characters in url which causes 404 errors.
 * This filter will remove UTF-8 characters from filename before saving it.
 * 
 * @see https://core.trac.wordpress.org/ticket/22363 Bug request
 *
 * @param string $filename Filename
 *
 * @return string Sanitized filename
 */
function sanitize_filename( $filename ) {

	$file_parts = explode( '.', $filename );
	$extension  = array_pop( $file_parts );
	$filename  = sanitize_title( preg_replace( '/[^A-Za-z0-9\-]/', '', join( '.', $file_parts ) ) );

	return sprintf('%s.%s', $filename, $extension);
}

add_filter( 'sanitize_file_name', 'sanitize_filename' );