ConcurrentModificationException

[PerMildner]

org.eclipse.swt.SWTException: Failed to execute runnable (java.util.ConcurrentModificationException)
at org.eclipse.swt.SWT.error(SWT.java:4083)
at org.eclipse.swt.SWT.error(SWT.java:3998)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:137)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3593)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3286)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2640)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2604)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2438)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:671)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:664)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:115)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:369)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:620)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:575)
at org.eclipse.equinox.launcher.Main.run(Main.java:1408)
Caused by: java.util.ConcurrentModificationException
at org.eclipse.emf.common.util.AbstractEList$EIterator.checkModCount(AbstractEList.java:762)
at org.eclipse.emf.common.util.AbstractEList$EIterator.doNext(AbstractEList.java:710)
at org.eclipse.emf.common.util.AbstractEList$EIterator.next(AbstractEList.java:696)
at org.eclipse.emf.edit.provider.ItemProviderAdapter.getChildren(ItemProviderAdapter.java:340)
at org.eclipse.emf.edit.provider.ItemProviderAdapter.getElements(ItemProviderAdapter.java:310)
at org.eclipse.emf.edit.ui.provider.AdapterFactoryContentProvider.getElements(AdapterFactoryContentProvider.java:160)
at org.eclipse.jface.viewers.StructuredViewer.getRawChildren(StructuredViewer.java:989)
at org.eclipse.jface.viewers.ColumnViewer.getRawChildren(ColumnViewer.java:703)
at org.eclipse.jface.viewers.AbstractTreeViewer.getRawChildren(AbstractTreeViewer.java:1332)
at org.eclipse.jface.viewers.TreeViewer.getRawChildren(TreeViewer.java:391)
at org.eclipse.jface.viewers.StructuredViewer.getFilteredChildren(StructuredViewer.java:896)
at org.eclipse.jface.viewers.AbstractTreeViewer.getSortedChildren(AbstractTreeViewer.java:601)
at org.eclipse.jface.viewers.AbstractTreeViewer.updateChildren(AbstractTreeViewer.java:2581)
at org.eclipse.jface.viewers.AbstractTreeViewer.internalRefreshStruct(AbstractTreeViewer.java:1867)
at org.eclipse.jface.viewers.TreeViewer.internalRefreshStruct(TreeViewer.java:721)
at org.eclipse.jface.viewers.AbstractTreeViewer.internalRefresh(AbstractTreeViewer.java:1842)
at org.eclipse.jface.viewers.AbstractTreeViewer.internalRefresh(AbstractTreeViewer.java:1799)
at org.eclipse.jface.viewers.StructuredViewer$8.run(StructuredViewer.java:1514)
at org.eclipse.jface.viewers.StructuredViewer.preservingSelection(StructuredViewer.java:1422)
at org.eclipse.jface.viewers.TreeViewer.preservingSelection(TreeViewer.java:403)
at org.eclipse.jface.viewers.StructuredViewer.preservingSelection(StructuredViewer.java:1383)
at org.eclipse.jface.viewers.StructuredViewer.refresh(StructuredViewer.java:1512)
at org.eclipse.jface.viewers.ColumnViewer.refresh(ColumnViewer.java:548)
at org.eclipse.emf.edit.ui.provider.AdapterFactoryContentProvider$ViewerRefresh.refresh(AdapterFactoryContentProvider.java:495)
at org.eclipse.emf.edit.ui.provider.AdapterFactoryContentProvider$ViewerRefresh.run(AdapterFactoryContentProvider.java:463)
at de.sebastianbenz.task.ui.views.ContentProvider$ExpandingViewerRefresh.run(ContentProvider.java:42)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:134)
... 22 more

[sebastianbenz]

Is this exception reproducible? If so, which steps are required?