Myeclipse jsp用Myeclipse visual Jsp Designer 打不开,只能用Myeclipse JSP Editor打开

今天做一个登陆验证，做到一半的时候，JSP报错，编译后。每个JSP页面都打不开，一打开，就提示Error opening the Editor,具体参数如

下：

java.lang.IllegalArgumentException: Argument not valid
    at org.eclipse.swt.SWT.error(SWT.java:3547)
    at org.eclipse.swt.SWT.error(SWT.java:3481)
    at org.eclipse.swt.SWT.error(SWT.java:3452)
    at org.eclipse.swt.custom.SashForm.setWeights(SashForm.java:374)
    at com.genuitec.eclipse.webdesigner3.editors.WebDesignerMultiPageEditor.configureSash(WebDesignerMultiPageEditor.java:637)
    at com.genuitec.eclipse.webdesigner3.editors.WebDesignerMultiPageEditor.createDesignPage(WebDesignerMultiPageEditor.java:573)
    at com.genuitec.eclipse.webdesigner3.editors.WebDesignerMultiPageEditor.createPages(WebDesignerMultiPageEditor.java:340)
    at org.eclipse.ui.part.MultiPageEditorPart.createPartControl(MultiPageEditorPart.java:283)
    at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:661)
    at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:426)
    at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:592)
    at org.eclipse.ui.internal.EditorAreaHelper.setVisibleEditor(EditorAreaHelper.java:263)
    at org.eclipse.ui.internal.EditorManager.setVisibleEditor(EditorManager.java:1405)
    at org.eclipse.ui.internal.EditorManager$5.runWithException(EditorManager.java:939)
    at org.eclipse.ui.internal.StartupThreading$StartupRunnable.run(StartupThreading.java:31)
    at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
    at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:129)
    at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3659)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3296)
    at org.eclipse.ui.application.WorkbenchAdvisor.openWindows(WorkbenchAdvisor.java:801)
    at org.eclipse.ui.internal.Workbench$25.runWithException(Workbench.java:1342)
    at org.eclipse.ui.internal.StartupThreading$StartupRunnable.run(StartupThreading.java:31)
    at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
    at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:129)
    at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3659)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3296)
    at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2309)
    at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2219)
    at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:466)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:289)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:461)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:106)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:169)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:106)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:76)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:363)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:508)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:447)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1173)
    at org.eclipse.equinox.launcher.Main.main(Main.java:1148)
在网上搜索说在widow --preferences--General--Editors--File Association--*.jsp中选中Myeclipse JSP Editors,设为Default就可以了，

虽然可以打开JSP，但是只JSP编码界面，而没有视图界面，在写界面代码时，看不到自己写的界面是什么样的。很急人的，而且每次打开JSP，

都要点击右键然后open with --Myeclipse JSP Editor，才能打开JSP文件，很是麻烦。目前我没没有找到真正的直接原因。等我找到时，我会告诉大家的。如果哪位有碰到同样的问题，请给点意见。

   今天请老师帮我解决，研究了半天，新建了一个空间，居然可以用了。老师说可能是.metadata这个文件有问题，那我也只能这么认为了。但具体错在哪里就不大清楚了。