XPDL文件解析报错，XML解析报错（org.xml.sax.SAXParseException）。

[埃克斯歪ForABAP]

org.xml.sax.SAXParseException: Content is not allowed in prolog.
at org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
at org.apache.xerces.jaxp.DocumentBuilderImpl.parse(Unknown Source)
at com.langchao.workflow.client.xml.XML.toDocument(XML.java:585)
at com.langchao.workflow.client.xml.XML.loadDocumentByXmlString(XML.java:561)
at com.langchao.workflow.plugin.jspform.WfDJspformMain.iniFormAdapter(WfDJspformMain.java:135)
at com.langchao.workflow.client.WfD.start(WfD.java:599)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
百度后发现是XML文件多出了BOM签名，用程序清除掉之后仍然报相同错误。JDK更换掉之后也不行，甚至把在测试机上运行正常的项目检出到本机上，仍然报这个错误。有大侠解释下？