Eclipse Startup Error

---

When I start eclipse, sometimes it does not start and throws error message like "An error has occured. See the log file ..\workspace\.metadata\.log".

.log
!ENTRY org.eclipse.core.resources 2 10035 2009-05-25 10:49:07.164!MESSAGE A workspace crash was detected. The previous session did not exit normally.
!ENTRY org.eclipse.osgi 4 0 2009-05-25 10:49:07.383!MESSAGE An error occurred while automatically activating bundle org.eclipse.core.resources (39).!STACK 0org.osgi.framework.BundleException: Exception in org.eclipse.core.internal.compatibility.PluginActivator.start() of bundle org.eclipse.core.resources. at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:1010)
.....
Caused by: org.eclipse.core.internal.dtree.ObjectNotFoundException: Tree element /Test/Person.class not found. at org.eclipse.core.internal.dtree.AbstractDataTree.handleNotFound(AbstractDataTree.java:257) at org.eclipse.core.internal.dtree.DeltaDataTree.getData(DeltaDataTree.java:585) at org.eclipse.core.internal.dtree.DataDeltaNode.asBackwardDelta(DataDeltaNode.java:50) at org.eclipse.core.internal.dtree.NoDataDeltaNode.asBackwardDelta(NoDataDeltaNode.java:59) at org.eclipse.core.internal.dtree.DataDeltaNode.asBackwardDelta(DataDeltaNode.java:47) at org.eclipse.core.internal.dtree.DeltaDataTree.asBackwardDelta(DeltaDataTree.java:88)
..........
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:985) ... 28 moreRoot exception:org.eclipse.core.internal.dtree.ObjectNotFoundException: Tree element /Test/Person.class not found. at org.eclipse.core.internal.dtree.AbstractDataTree.handleNotFound(AbstractDataTree.java:257) at org.eclipse.core.internal.dtree.DeltaDataTree.getData(DeltaDataTree.java:585)
.........
at org.eclipse.core.launcher.Main.main(Main.java:952)
!ENTRY org.eclipse.osgi 4 0 2009-05-25 10:49:07.383!MESSAGE Application error!STACK 1java.lang.NoClassDefFoundError: org/eclipse/core/resources/IContainer at org.eclipse.ui.internal.ide.IDEApplication.run(IDEApplication.java:96)
..........
!ENTRY org.eclipse.osgi 2 0 2009-05-25 10:49:07.493!MESSAGE The following is a complete list of bundles which are not resolved, see the prior log entry for the root cause if it exists:!
SUBENTRY 1 org.eclipse.osgi 2 0 2009-05-25 10:49:07.493!MESSAGE Bundle update@plugins/org.eclipse.core.filesystem.linux.x86_1.0.0.v20060603.jar [32] was not resolved.
!SUBENTRY 1 org.eclipse.osgi 2 0 2009-05-25 10:49:07.493!MESSAGE Bundle update@plugins/org.eclipse.core.filesystem.macosx_1.0.0.v20060603.jar [33] was not resolved.
!SUBENTRY 1 org.eclipse.osgi 2 0 2009-05-25 10:49:07.493!MESSAGE Bundle update@plugins/org.eclipse.jdt.launching.macosx_3.1.100.v20060605.jar [95] was not resolved.!
SUBENTRY 1 org.eclipse.osgi 2 0 2009-05-25 10:49:07.493!MESSAGE Bundle update@plugins/org.eclipse.swt.carbon.macosx_3.2.2.v3236.jar [179] was not resolved.!
SUBENTRY 1 org.eclipse.osgi 2 0 2009-05-25 10:49:07.493!MESSAGE Bundle update@plugins/org.eclipse.swt.gtk.linux.x86_3.2.2.v3236.jar [180] was not resolved.!
SUBENTRY 1 org.eclipse.osgi 2 0 2009-05-25 10:49:07.493!MESSAGE Bundle update@plugins/org.eclipse.ui.carbon_3.2.0.I20060605-1400.jar [192] was not resolved.!
SUBENTRY 1 org.eclipse.osgi 2 0 2009-05-25 10:49:07.493!MESSAGE Bundle update@plugins/org.eclipse.update.core.linux_3.2.0.v20060605.jar [212] was not resolved.

How to Resolve
Delete the following files/folders:
1. \workspace\.metadata\.plugins\org.eclipse.core.resources\.snap
2. \workspace\.metadata\.plugins\org.eclipse.core.resources\.root\.markers.snap

Now start eclipse. It should start else problem is something else.