我正在尝试更新已安装的软件并安装插件，以便全新安装eclipse 3.4.2。每当我尝试更新/安装时，我都会收到此错误：
“准备操作时遇到意外错误.org.eclipse.core.runtime.AssertionFailedException”
详细说明： “准备操作时遇到意外错误.null argument：”
日志文件条目
org.eclipse.core.runtime.AssertionFailedException: null argument:
at org.eclipse.core.runtime.Assert.isNotNull(Assert.java:86)
at org.eclipse.core.runtime.Assert.isNotNull(Assert.java:74)
at org.eclipse.equinox.internal.provisional.p2.metadata.ProvidedCapability.<init>(ProvidedCapability.java:25)
at org.eclipse.equinox.internal.provisional.p2.metadata.MetadataFactory.createProvidedCapability(MetadataFactory.java:189)
at org.eclipse.equinox.internal.p2.metadata.repository.io.MetadataParser$ProvidedCapabilityHandler.<init>(MetadataParser.java:483)
at org.eclipse.equinox.internal.p2.metadata.repository.io.MetadataParser$ProvidedCapabilitiesHandler.startElement(MetadataParser.java:469)
at org.eclipse.equinox.internal.p2.persistence.XMLParser$AbstractHandler.startElement(XMLParser.java:171)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown Source)
at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryIO$Parser.parse(MetadataRepositoryIO.java:193)
at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryIO.read(MetadataRepositoryIO.java:56)
at org.eclipse.equinox.internal.provisional.spi.p2.metadata.repository.SimpleMetadataRepositoryFactory.validateAndLoad(SimpleMetadataRepositoryFactory.java:116)
at org.eclipse.equinox.internal.provisional.spi.p2.metadata.repository.SimpleMetadataRepositoryFactory.load(SimpleMetadataRepositoryFactory.java:85)
at org.eclipse.equinox.internal.p2.updatesite.metadata.UpdateSiteMetadataRepository.initializeMetadataRepository(UpdateSiteMetadataRepository.java:187)
at org.eclipse.equinox.internal.p2.updatesite.metadata.UpdateSiteMetadataRepository.<init>(UpdateSiteMetadataRepository.java:67)
at org.eclipse.equinox.internal.p2.updatesite.metadata.UpdateSiteMetadataRepositoryFactory.load(UpdateSiteMetadataRepositoryFactory.java:48)
at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.loadRepository(MetadataRepositoryManager.java:485)
at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.loadRepository(MetadataRepositoryManager.java:452)
at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.loadRepository(MetadataRepositoryManager.java:435)
at org.eclipse.equinox.internal.p2.director.SimplePlanner.gatherAvailableInstallableUnits(SimplePlanner.java:196)
at org.eclipse.equinox.internal.p2.director.SimplePlanner.getProvisioningPlan(SimplePlanner.java:235)
at org.eclipse.equinox.internal.provisional.p2.ui.operations.ProvisioningUtil.getProvisioningPlan(ProvisioningUtil.java:210)
at org.eclipse.equinox.internal.provisional.p2.ui.actions.InstallAction.computeProvisioningPlan(InstallAction.java:80)
at org.eclipse.equinox.internal.provisional.p2.ui.actions.InstallAction.getProvisioningPlan(InstallAction.java:130)
at org.eclipse.equinox.internal.provisional.p2.ui.actions.ProfileModificationAction$1.run(ProfileModificationAction.java:61)
at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)
导致此问题的原因是什么？如何解决？
答案 0 :(得分：2)
我通过从存档包中重新安装eclipse来解决我的问题。我使用相同的程序（据我所知）重新安装，因为我第一次使用，但这次尝试更新和安装功能时没有错误。
答案 1 :(得分：0)
p2几乎无法在3.4.x中运行（并且在3.5的早期仍有很多错误，例如this one。） 你有机会尝试使用3.5.1 eclipse安装吗？