An invalid XML character (Unicode: 0xc) was found

Parsing an XML file using the Java DOM parser results in:

[Fatal Error] os__flag_8c.xml:103:135: An invalid XML character (Unicode: 0xc) was found in the element content of the document.
org.xml.sax.SAXParseException: An invalid XML character (Unicode: 0xc) was found in the element content of the document.
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(Unknown Source)
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(Unknown Source)
    at javax.xml.parsers.DocumentBuilder.parse(Unknown Source)

Solution

There are a few characters that are dissallowed in XML documents, even when you encapsulate data in CDATA-blocks.

If you generated the document you will need to ~~entity encode it or~~ strip it out. If you have an errorneous document, you should strip away these characters before trying to parse it.

See dolmens answer in this thread: Invalid Characters in XML

Where he links to this article: http://www.w3.org/TR/xml/#charsets

Basically, all characters below 0x20 is disallowed, except 0x9 (TAB), 0xA (CR?), 0xD (LF?)