The XML file should not have any other character before <?xml, even no spaces, newlines or unicode byte order marks. If you‘re not seeing anything, the it‘s most likely the BOM. Re-save the XML file as ASCII or as Unicode-without-BOM (and don‘t use Windows notepad to create and edit XML!)
来自网站http://stackoverflow.com/questions/19918455/errorthe-processing-instruction-target-matching-xxmmll-is-not-allowed
原文：http://www.cnblogs.com/nan-qz111/p/4585580.html