我有一个java + appium项目，但是当我运行它时，它会抛出一个错误，
我已经尝试了Project->Clean并再次运行，但它对我不起作用。
我还尝试检查 testng.xml ，但没有错。
错误追踪：
at org.testng.xml.XmlClass.loadClass(XmlClass.java:81)
at org.testng.xml.XmlClass.init(XmlClass.java:73)
at org.testng.xml.XmlClass.<init>(XmlClass.java:59)
at org.testng.xml.TestNGContentHandler.startElement(TestNGContentHandler.j ava:543)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:509)
at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:182)
at com.sun.org.apache.xerces.internal.impl.dtd.XMLDTDValidator.emptyElement(XMLDTDValidator.java:766)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1339)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2784)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:841)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:770)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:643)
at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(SAXParserImpl.java:327)
at javax.xml.parsers.SAXParser.parse(SAXParser.java:195)
at org.testng.xml.SuiteXmlParser.parse(SuiteXmlParser.java:17)
at org.testng.xml.SuiteXmlParser.parse(SuiteXmlParser.java:10)
at org.testng.xml.Parser.parse(Parser.java:172)
at org.testng.TestNG.initializeSuitesAndJarFile(TestNG.java:311)
at org.testng.remote.AbstractRemoteTestNG.initialize(AbstractRemoteTestNG.java:136)
at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:97)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)