## How to resolve NoClassDefFoundError: org/eclipse/core/resources/IContainer

If your Eclipse IDE crashed for some reason, you may see below error during startup.

```!ENTRY org.eclipse.osgi 4 0 2015-08-15 21:37:18.834
!MESSAGE Application error
!STACK 1
java.lang.NoClassDefFoundError: org/eclipse/core/resources/IContainer
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:136)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)

```

This error occurs if you had selected "Use this as the default and do not ask again" option during Eclipse startup.

Eclipse is trying to load the workspace. But the workspace has some error so Eclipse is unable to load it. So how to force eclipse to prompt for new workspace? Here is the simple step for this,

Open <Eclipse_root_dir>\configuration\.settings\org.eclipse.ui.ide.prefs file in Notepad and set SHOW_WORKSPACE_SELECTION_DIALOG=true

Here is the screenshot;

Now Eclipse will ask you to select the workspace during startup.