- or -
Re-encode the XML data as proper UTF-8.
Most often, you see this problem if you are working with data that uses the simple "iso-8859-1" encoding scheme. In this case, the quickest solution is usually the first listed prior in the RESOLUTION section. For example, use the following XML declaration:
<?xml version="1.0" encoding="iso-8859-1" ?>
Alternatively, you can encode each of those characters using the numeric entity reference. For example, you can take the special character á, use <test>á</test> (decimal version) or <test> á</test> (hex version).