一. 报错
!ENTRY org.eclipse.oomph.p2.core 4 0 2020-05-25 16:05:41.038
!MESSAGE FrameworkEvent ERROR
!STACK 0
org.osgi.framework.BundleException: Exception in org.eclipse.oomph.p2.internal.core.P2CorePlugin$Implementation.stop() of bundle org.eclipse.oomph.p2.core.
at org.eclipse.osgi.internal.framework.BundleContextImpl.stop(BundleContextImpl.java:919)
at org.eclipse.osgi.internal.framework.EquinoxBundle.stopWorker0(EquinoxBundle.java:1027)
at org.eclipse.osgi.internal.framework.EquinoxBundle$EquinoxModule.stopWorker(EquinoxBundle.java:370)
at org.eclipse.osgi.container.Module.doStop(Module.java:653)
at org.eclipse.osgi.container.Module.stop(Module.java:515)
at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.decStartLevel(ModuleContainer.java:1861)
at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.doContainerStartLevel(ModuleContainer.java:1753)
at org.eclipse.osgi.container.SystemModule.stopWorker(SystemModule.java:275)
at org.eclipse.osgi.internal.framework.EquinoxBundle$SystemBundle$EquinoxSystemModule.stopWorker(EquinoxBundle.java:202)
at org.eclipse.osgi.container.Module.doStop(Module.java:653)
at org.eclipse.osgi.container.Module.stop(Module.java:515)
at org.eclipse.osgi.container.SystemModule.stop(SystemModule.java:207)
at org.eclipse.osgi.internal.framework.EquinoxBundle$SystemBundle$EquinoxSystemModule$1.run(EquinoxBundle.java:220)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoClassDefFoundError: org/eclipse/emf/ecore/resource/Resource
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.defineClass(ModuleClassLoader.java:278)
at org.eclipse.osgi.internal.loader.classpath.ClasspathManager.defineClass(ClasspathManager.java:716)
at org.eclipse.osgi.internal.loader.classpath.ClasspathManager.findClassImpl(ClasspathManager.java:639)
at org.eclipse.osgi.internal.loader.classpath.ClasspathManager.findLocalClassImpl(ClasspathManager.java:607)
at org.eclipse.osgi.internal.loader.classpath.ClasspathManager.findLocalClassImpl(ClasspathManager.java:587)
at org.eclipse.osgi.internal.loader.classpath.ClasspathManager.findLocalClass(ClasspathManager.java:566)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.findLocalClass(ModuleClassLoader.java:330)
at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:396)
at org.eclipse.osgi.internal.loader.sources.SingleSourcePackage.loadClass(SingleSourcePackage.java:41)
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:470)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:423)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:415)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:155)
at java.lang.ClassLoader.loadClass(Unknown Source)
at org.eclipse.oomph.p2.internal.core.AgentImpl$2.createElement(AgentImpl.java:169)
at org.eclipse.oomph.p2.internal.core.AgentImpl$2.createElement(AgentImpl.java:1)
at org.eclipse.oomph.p2.internal.core.PersistentMap.loadElement(PersistentMap.java:202)
at org.eclipse.oomph.p2.internal.core.AgentImpl$2.loadElement(AgentImpl.java:176)
at org.eclipse.oomph.p2.internal.core.AgentImpl$2.loadElement(AgentImpl.java:1)
at org.eclipse.oomph.p2.internal.core.PersistentMap$1.handleKey(PersistentMap.java:83)
at org.eclipse.oomph.p2.internal.core.PersistentMap.load(PersistentMap.java:243)
at org.eclipse.oomph.p2.internal.core.PersistentMap.load(PersistentMap.java:79)
at org.eclipse.oomph.p2.internal.core.AgentImpl.<init>(AgentImpl.java:187)
at org.eclipse.oomph.p2.internal.core.AgentManagerImpl$1.createElement(AgentManagerImpl.java:91)
at org.eclipse.oomph.p2.internal.core.AgentManagerImpl$1.createElement(AgentManagerImpl.java:1)
at org.eclipse.oomph.p2.internal.core.PersistentMap.loadElement(PersistentMap.java:202)
at org.eclipse.oomph.p2.internal.core.AgentManagerImpl$1.loadElement(AgentManagerImpl.java:82)
at org.eclipse.oomph.p2.internal.core.AgentManagerImpl$1.loadElement(AgentManagerImpl.java:1)
at org.eclipse.oomph.p2.internal.core.PersistentMap$1.handleKey(PersistentMap.java:83)
at org.eclipse.oomph.p2.internal.core.PersistentMap.load(PersistentMap.java:243)
at org.eclipse.oomph.p2.internal.core.PersistentMap.load(PersistentMap.java:79)
at org.eclipse.oomph.p2.internal.core.AgentManagerImpl.<init>(AgentManagerImpl.java:141)
at org.eclipse.oomph.p2.internal.core.AgentManagerImpl.<init>(AgentManagerImpl.java:63)
at org.eclipse.oomph.p2.core.P2Util.getAgentManager(P2Util.java:59)
at org.eclipse.oomph.p2.internal.core.P2CorePlugin$Implementation.stop(P2CorePlugin.java:168)
at org.eclipse.osgi.internal.framework.BundleContextImpl$4.run(BundleContextImpl.java:899)
at org.eclipse.osgi.internal.framework.BundleContextImpl$4.run(BundleContextImpl.java:1)
at java.security.AccessController.doPrivileged(Native Method)
at org.eclipse.osgi.internal.framework.BundleContextImpl.stop(BundleContextImpl.java:891)
... 13 more
二. 解决方法
启动eclipse时报如上错误，，将eclipse安装目录下的 configurationorg.eclipse.osgi.manager 下的文件删除掉，重启eclipse就可以了（我这里测试是可以的。）
注意：删除以前 最好将eclipse安装目录下的configurationorg.eclipse.osgi.manager 下的文件做备份，防止不是这三个文件影响的。