java.lang.NullPointerException when launching Eclipse

Question

I'm using Eclipse Juno and I get this error when I launch it on a certain workspace:

An error has occurred. See error log for more details.

java.lang.NullPointerException

Other workspaces that are checked out from the same SVN repository work well. Does anyone know why this might happen?

In the workspace log, I get the following exception:

!ENTRY org.eclipse.m2e.logback.appender 4 0 2014-03-11 13:26:25.798 !MESSAGE Could not add repository index

!ENTRY org.eclipse.ui.workbench 4 2 2014-03-11 13:26:37.470 !MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.ui.workbench". !STACK 0 java.lang.NullPointerException at org.tigris.subversion.subclipse.ui.history.SVNHistoryPage$2.getElements(SVNHistoryPage.java:631) at org.eclipse.jface.viewers.StructuredViewer.getRawChildren(StructuredViewer.java:1010) at org.eclipse.jface.viewers.ColumnViewer.getRawChildren(ColumnViewer.java:703) at org.eclipse.jface.viewers.AbstractTableViewer.getRawChildren(AbstractTableViewer.java:1087) at org.eclipse.jface.viewers.StructuredViewer.getFilteredChildren(StructuredViewer.java:917) at org.eclipse.jface.viewers.StructuredViewer.getSortedChildren(StructuredViewer.java:1067) at org.eclipse.jface.viewers.AbstractTableViewer.internalRefreshAll(AbstractTableViewer.java:701) at org.eclipse.jface.viewers.AbstractTableViewer.internalRefresh(AbstractTableViewer.java:649) at org.eclipse.jface.viewers.AbstractTableViewer.internalRefresh(AbstractTableViewer.java:636) at org.eclipse.jface.viewers.AbstractTableViewer$2.run(AbstractTableViewer.java:592) 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)

Answer 1

Solved: cleaned up my .metadata folder and re-imported projects in eclipse