Project cannot be run in Eclipse after running project using ant, projects still can be launch using ANT

This is the sample error code on running LeadTest.java

[RemoteTestNG] detected TestNG version 7.0.0
org.testng.TestNGException:
Cannot find class in classpath: com.qtpselenium.zoho.project.testcases.LeadTest
at org.testng.xml.XmlClass.loadClass(XmlClass.java:75)
at org.testng.xml.XmlClass.init(XmlClass.java:67)
at org.testng.xml.XmlClass.<init>(XmlClass.java:54)
at org.testng.xml.TestNGContentHandler.startElement(TestNGContentHandler.java:541)
at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.emptyElement(Unknown Source)
at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
at org.apache.xerces.jaxp.SAXParserImpl.parse(Unknown Source)
at java.xml/javax.xml.parsers.SAXParser.parse(SAXParser.java:197)
at org.testng.xml.XMLParser.parse(XMLParser.java:39)
at org.testng.xml.SuiteXmlParser.parse(SuiteXmlParser.java:16)
at org.testng.xml.SuiteXmlParser.parse(SuiteXmlParser.java:9)
at org.testng.xml.Parser.parse(Parser.java:160)
at org.testng.xml.Parser.parse(Parser.java:246)
at org.testng.TestNG.parseSuite(TestNG.java:298)
at org.testng.TestNG.initializeSuitesAndJarFile(TestNG.java:350)
at org.testng.TestNG.initializeEverything(TestNG.java:980)
at org.testng.remote.support.RemoteTestNG6_12.initialize(RemoteTestNG6_12.java:22)
at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:98)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)