[求助]TOMCAT这个异常是怎么什么问题啊

TOMCAT这个异常是怎么什么问题啊怎么说我这个xX][mM][lL]"
不允许啊！这个东西是什么啊。我是重网上下的以个源码

严重: Parse Fatal Error at line 1 column 8: The processing instruction target matching "[xX][mM][lL]" is not allowed.
org.xml.sax.SAXParseException: The processing instruction target matching "[xX][mM][lL]" is not allowed.
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:236)
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:215)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:386)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:316)
at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1438)
at com.sun.org.apache.xerces.internal.impl.XMLScanner.scanPIData(XMLScanner.java:689)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanPIData(XMLDocumentFragmentScannerImpl.java:750)
at com.sun.org.apache.xerces.internal.impl.XMLScanner.scanPI(XMLScanner.java:664)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDispatcher.dispatch(XMLDocumentScannerImpl.java:845)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:368)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:834)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:764)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:148)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1242)
at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1545)
at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:565)
at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:535)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:470)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1122)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:310)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1021)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:718)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1013)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:442)
at org.apache.catalina.core.StandardService.start(StandardService.java:450)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:709)
at org.apache.catalina.startup.Catalina.start(Catalina.java:551)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:294)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:432)
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网上下的一般80%不能用
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是什么情况下的异常呢

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就是在运行服务的时候

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TOMCAT没安装好
服务器没有启动
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别的服务都可以用啊
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别的什么服务！！
直接从官方网站下载的东西，只要是路径配置没问题，我想不应该出什么问题的！
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