出现错误如下：
提示错误信息：Could not open the editor: An unexpected exception was thrown.
java.lang.NullPointerException
at com.genuitec.eclipse.struts.editor.modeler.model.StrutsConfigDiagram.processAction(StrutsConfigDiagram.java:574)
at com.genuitec.eclipse.struts.editor.modeler.model.StrutsConfigDiagram.synchronizeDiagram(StrutsConfigDiagram.java:479)
at com.genuitec.eclipse.struts.editor.modeler.model.StrutsConfigDiagram.differedSynchronize(StrutsConfigDiagram.java:120)
at com.genuitec.eclipse.struts.editor.multipage.StrutsConfigEditor.createPages(StrutsConfigEditor.java:296)
at org.eclipse.ui.part.MultiPageEditorPart.createPartControl(MultiPageEditorPart.java:357)
at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:662)
at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:462)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:313)
at org.eclipse.ui.internal.presentations.PresentablePart.setVisible(PresentablePart.java:180)
at org.eclipse.ui.internal.presentations.util.PresentablePartFolder.select(PresentablePartFolder.java:270)
at org.eclipse.ui.internal.presentations.util.LeftToRightTabOrder.select(LeftToRightTabOrder.java:65)
at org.eclipse.ui.internal.presentations.util.TabbedStackPresentation.selectPart(TabbedStackPresentation.java:473)
at org.eclipse.ui.internal.PartStack.refreshPresentationSelection(PartStack.java:1256)
at org.eclipse.ui.internal.PartStack.setSelection(PartStack.java:1209)
at org.eclipse.ui.internal.PartStack.showPart(PartStack.java:1608)
at org.eclipse.ui.internal.PartStack.add(PartStack.java:499)
at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:103)
at org.eclipse.ui.internal.PartStack.add(PartStack.java:485)
at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:112)......
解决办法：
struts-config.xml目录上面点击右键--> open with -->myeclipse xml editor
myEclipse 打不开struts-config.xml 报Could not open the editor: An unexpected exception was thrown 错误(转载)
原文：http://www.cnblogs.com/waiwai1015/p/4632117.html