ubuntu 16.04 LTS启动Eclipse Neno.3报错"An error has occurred. See the log file",具体如下图所示：
此时我们查看/home/longsky/workspace/.metadata/.log，可以看到里面的内容如下：
!ENTRY org.eclipse.osgi 4 0 2017-04-08 16:27:06.246 !MESSAGE Application error !STACK 1 java.lang.NoClassDefFoundError: org/eclipse/core/resources/IContainer at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:139) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:388) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:673) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:610) at org.eclipse.equinox.launcher.Main.run(Main.java:1519) at org.eclipse.equinox.launcher.Main.main(Main.java:1492) Caused by: java.lang.ClassNotFoundException: An error occurred while automatically activating bundle org.eclipse.core.resources (104). at org.eclipse.osgi.internal.hooks.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:116) at org.eclipse.osgi.internal.loader.classpath.ClasspathManager.findLocalClass(ClasspathManager.java:529) at org.eclipse.osgi.internal.loader.ModuleClassLoader.findLocalClass(ModuleClassLoader.java:325) at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:345) at org.eclipse.osgi.internal.loader.sources.SingleSourcePackage.loadClass(SingleSourcePackage.java:36) at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:419) at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:372) at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:364) at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:161) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ... 14 more Caused by: org.osgi.framework.BundleException: Exception in org.eclipse.core.resources.ResourcesPlugin.start() of bundle org.eclipse.core.resources. at org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator(BundleContextImpl.java:795) at org.eclipse.osgi.internal.framework.BundleContextImpl.start(BundleContextImpl.java:724) at org.eclipse.osgi.internal.framework.EquinoxBundle.startWorker0(EquinoxBundle.java:932) at org.eclipse.osgi.internal.framework.EquinoxBundle$EquinoxModule.startWorker(EquinoxBundle.java:309) at org.eclipse.osgi.container.Module.doStart(Module.java:581) at org.eclipse.osgi.container.Module.start(Module.java:449) at org.eclipse.osgi.framework.util.SecureAction.start(SecureAction.java:470) at org.eclipse.osgi.internal.hooks.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:107) ... 23 more Caused by: org.eclipse.core.internal.dtree.ObjectNotFoundException: Tree element '/caffe/tools/extra/summarize.py' not found. at org.eclipse.core.internal.dtree.AbstractDataTree.handleNotFound(AbstractDataTree.java:257) at org.eclipse.core.internal.dtree.DeltaDataTree.getData(DeltaDataTree.java:596) at org.eclipse.core.internal.dtree.DataDeltaNode.asBackwardDelta(DataDeltaNode.java:51) at org.eclipse.core.internal.dtree.NoDataDeltaNode.asBackwardDelta(NoDataDeltaNode.java:60) at org.eclipse.core.internal.dtree.NoDataDeltaNode.asBackwardDelta(NoDataDeltaNode.java:60) at org.eclipse.core.internal.dtree.NoDataDeltaNode.asBackwardDelta(NoDataDeltaNode.java:60) at org.eclipse.core.internal.dtree.DataDeltaNode.asBackwardDelta(DataDeltaNode.java:48) at org.eclipse.core.internal.dtree.DeltaDataTree.asBackwardDelta(DeltaDataTree.java:88) at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:832) at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:831) at org.eclipse.core.internal.dtree.DeltaDataTree.reroot(DeltaDataTree.java:808) at org.eclipse.core.internal.watson.ElementTree.immutable(ElementTree.java:519) at org.eclipse.core.internal.resources.SaveManager.restore(SaveManager.java:742) at org.eclipse.core.internal.resources.SaveManager.startup(SaveManager.java:1587) at org.eclipse.core.internal.resources.Workspace.startup(Workspace.java:2399) at org.eclipse.core.internal.resources.Workspace.open(Workspace.java:2156) at org.eclipse.core.resources.ResourcesPlugin.start(ResourcesPlugin.java:464) at org.eclipse.osgi.internal.framework.BundleContextImpl$3.run(BundleContextImpl.java:774) at org.eclipse.osgi.internal.framework.BundleContextImpl$3.run(BundleContextImpl.java:1) at java.security.AccessController.doPrivileged(Native Method) at org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator(BundleContextImpl.java:767) ... 30 more !SESSION 2017-04-08 16:27:14.692 ----------------------------------------------- eclipse.buildId=4.6.2.M20161124-1400 java.version=1.8.0_121 java.vendor=Oracle Corporation BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=zh_CN Framework arguments: -product org.eclipse.epp.package.cpp.product Command-line arguments: -os linux -ws gtk -arch x86_64 -product org.eclipse.epp.package.cpp.product
这是由于丢失部分插件文件，或者插件文件损坏导致的。
解决方法:
删除指定的工作目录下.metadata的文件夹下所有文件,然后重新启动Eclipse!
比如：
$ cd ~/workspace $ rm -rf .metadata