关键字：
弹出对话框：An error has occurred.See the log file…/.log（让你看日志）
org.osgi.framework.BundleException: Exception in org.eclipse.core.resources.ResourcesPlugin.start() of bundle org.eclipse.core.resources. 主要的报错信息。
myeclipse启动报错的情况很多，如果你所看到的与我上面写的一致，请往下看。
直接删除.plugins中的所有文件后重启。问题是原来的项目需要重新导入。由于各种各样的原因，我预计需要花整一天的时间来导入，这是不可接受的。于是找到了第二种方法。
先把.plugins中的内容备份一下。再把org.eclipse.core.resources 中的.snap，以及其中的.root文件夹中除了.indexes外的文件删除。之后重启。
重启之后，我这边的情况是工作空间中的项目都没了，但是这些项目依然在工作空间内。只需要刷出来就行了。
具体方法是：File->Import->General->Existing Projects info Workspace->Select root dirctory，找到对应项目，然后在projects框中勾选，点下右边的Refresh，再点击finish就行了。
下面是我的.log中的完整报错信息，可以对照一下，如果报错不一致，不保证上述方法有效。一致了，也不保证…myeclipse这东西真的有点迷。
!ENTRY org.eclipse.osgi 4 0 2018-08-01 16:13:27.329
!MESSAGE An error occurred while automatically activating bundle org.eclipse.core.resources (413).
!STACK 0
org.osgi.framework.BundleException: Exception in org.eclipse.core.resources.ResourcesPlugin.start() of bundle org.eclipse.core.resources.
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:734)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:683)
at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:381)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:300)
at org.eclipse.osgi.framework.util.SecureAction.start(SecureAction.java:440)
at org.eclipse.osgi.internal.loader.BundleLoader.setLazyTrigger(BundleLoader.java:263)
at org.eclipse.core.runtime.internal.adaptor.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:107)
at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass(ClasspathManager.java:469)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.findLocalClass(DefaultClassLoader.java:216)
at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:395)
at org.eclipse.osgi.internal.loader.SingleSourcePackage.loadClass(SingleSourcePackage.java:35)
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:461)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:421)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:412)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:125)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
at org.eclipse.equinox.launcher.Main.run(Main.java:1438)
at org.eclipse.equinox.launcher.Main.main(Main.java:1414)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.genuitec.pulse.eclipse.launcher.Main.main(Main.java:110)
Caused by: org.eclipse.core.internal.resources.ResourceException: Problems reading project tree.
at org.eclipse.core.internal.resources.WorkspaceTreeReader_2.readTree(WorkspaceTreeReader_2.java:125)
at org.eclipse.core.internal.resources.SaveManager.restoreTree(SaveManager.java:1000)
at org.eclipse.core.internal.resources.SaveManager.restore(SaveManager.java:687)
at org.eclipse.core.internal.resources.SaveManager.startup(SaveManager.java:1528)
at org.eclipse.core.internal.resources.Workspace.startup(Workspace.java:2502)
at org.eclipse.core.internal.resources.Workspace.open(Workspace.java:2251)
at org.eclipse.core.resources.ResourcesPlugin.start(ResourcesPlugin.java:439)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl$1.run(BundleContextImpl.java:711)
at java.security.AccessController.doPrivileged(Native Method)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:702)
... 34 more
Caused by: java.io.EOFException
at java.io.DataInputStream.readByte(DataInputStream.java:250)
at org.eclipse.core.internal.dtree.DataTreeReader.readNumber(DataTreeReader.java:130)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:87)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readTree(DataTreeReader.java:147)
at org.eclipse.core.internal.watson.ElementTreeReaderImpl_1.readDelta(ElementTreeReaderImpl_1.java:43)
at org.eclipse.core.internal.watson.ElementTreeReader.readDelta(ElementTreeReader.java:86)
at org.eclipse.core.internal.watson.ElementTreeReaderImpl_1.readDeltaChain(ElementTreeReaderImpl_1.java:88)
at org.eclipse.core.internal.watson.ElementTreeReader.readDeltaChain(ElementTreeReader.java:110)
at org.eclipse.core.internal.resources.WorkspaceTreeReader_1.readTrees(WorkspaceTreeReader_1.java:233)
at org.eclipse.core.internal.resources.WorkspaceTreeReader_2.readTree(WorkspaceTreeReader_2.java:104)
... 43 more
Root exception:
org.eclipse.core.internal.resources.ResourceException(null)[567]: java.io.EOFException
at java.io.DataInputStream.readByte(DataInputStream.java:250)
at org.eclipse.core.internal.dtree.DataTreeReader.readNumber(DataTreeReader.java:130)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:87)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readNode(DataTreeReader.java:103)
at org.eclipse.core.internal.dtree.DataTreeReader.readTree(DataTreeReader.java:147)
at org.eclipse.core.internal.watson.ElementTreeReaderImpl_1.readDelta(ElementTreeReaderImpl_1.java:43)
at org.eclipse.core.internal.watson.ElementTreeReader.readDelta(ElementTreeReader.java:86)
at org.eclipse.core.internal.watson.ElementTreeReaderImpl_1.readDeltaChain(ElementTreeReaderImpl_1.java:88)
at org.eclipse.core.internal.watson.ElementTreeReader.readDeltaChain(ElementTreeReader.java:110)
at org.eclipse.core.internal.resources.WorkspaceTreeReader_1.readTrees(WorkspaceTreeReader_1.java:233)
at org.eclipse.core.internal.resources.WorkspaceTreeReader_2.readTree(WorkspaceTreeReader_2.java:104)
at org.eclipse.core.internal.resources.SaveManager.restoreTree(SaveManager.java:1000)
at org.eclipse.core.internal.resources.SaveManager.restore(SaveManager.java:687)
at org.eclipse.core.internal.resources.SaveManager.startup(SaveManager.java:1528)
at org.eclipse.core.internal.resources.Workspace.startup(Workspace.java:2502)
at org.eclipse.core.internal.resources.Workspace.open(Workspace.java:2251)
at org.eclipse.core.resources.ResourcesPlugin.start(ResourcesPlugin.java:439)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl$1.run(BundleContextImpl.java:711)
at java.security.AccessController.doPrivileged(Native Method)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:702)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:683)
at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:381)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:300)
at org.eclipse.osgi.framework.util.SecureAction.start(SecureAction.java:440)
at org.eclipse.osgi.internal.loader.BundleLoader.setLazyTrigger(BundleLoader.java:263)
at org.eclipse.core.runtime.internal.adaptor.EclipseLazyStarter.postFindLocalClass(EclipseLazyStarter.java:107)
at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass(ClasspathManager.java:469)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.findLocalClass(DefaultClassLoader.java:216)
at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(BundleLoader.java:395)
at org.eclipse.osgi.internal.loader.SingleSourcePackage.loadClass(SingleSourcePackage.java:35)
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:461)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:421)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:412)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:125)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
at org.eclipse.equinox.launcher.Main.run(Main.java:1438)
at org.eclipse.equinox.launcher.Main.main(Main.java:1414)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.genuitec.pulse.eclipse.launcher.Main.main(Main.java:110)