java.lang.IllegalStateException: This method must be called in the event thread.
   at org.netbeans.modules.j2ee.core.api.support.progress.ProgressSupport.invoke(ProgressSupport.java:109)
   at org.netbeans.modules.j2ee.core.api.support.progress.ProgressSupport.invoke(ProgressSupport.java:94)
   at org.netbeans.modules.j2ee.common.DatasourceUIHelper.fetchDataSources(DatasourceUIHelper.java:461)
   at org.netbeans.modules.j2ee.common.DatasourceUIHelper.connect(DatasourceUIHelper.java:473)
   at org.netbeans.modules.j2ee.common.DatasourceUIHelper.connect(DatasourceUIHelper.java:423)
   at org.netbeans.modules.web.project.WebJPADataSourceSupport.connect(WebJPADataSourceSupport.java:72)
   at org.netbeans.modules.j2ee.persistence.wizard.unit.PersistenceUnitWizardPanelDS.connectDatasources(PersistenceUnitWizardPanelDS.java:123)
   at org.netbeans.modules.j2ee.persistence.wizard.unit.PersistenceUnitWizardPanelDS.<init>(PersistenceUnitWizardPanelDS.java:91)
   at org.netbeans.modules.j2ee.persistence.wizard.unit.PersistenceUnitWizardPanelDS.<init>(PersistenceUnitWizardPanelDS.java:80)
   at org.netbeans.modules.j2ee.persistence.wizard.unit.PersistenceUnitWizardDescriptor.getComponent(PersistenceUnitWizardDescriptor.java:92)
   at org.netbeans.modules.j2ee.core.api.support.wizard.Wizards.setSteps(Wizards.java:100)
   at org.netbeans.modules.j2ee.core.api.support.wizard.Wizards.mergeSteps(Wizards.java:94)
   at org.netbeans.modules.j2ee.persistence.wizard.entity.EntityWizard.initialize(EntityWizard.java:156)
   at org.openide.loaders.TemplateWizard$InstantiatingIteratorBridge.initialize(TemplateWizard.java:1035)
   at org.openide.loaders.TemplateWizardIterImpl.setIterator(TemplateWizardIterImpl.java:103)
   at org.openide.loaders.TemplateWizardIteratorWrapper.setIterator(TemplateWizardIteratorWrapper.java:79)
   at org.openide.loaders.TemplateWizard.setTemplateImpl(TemplateWizard.java:204)
   at org.openide.loaders.TemplateWizard.setTemplate(TemplateWizard.java:222)
   at org.openide.loaders.TemplateWizard.instantiateImpl(TemplateWizard.java:472)
   at org.openide.loaders.TemplateWizard.instantiate(TemplateWizard.java:388)
   at org.netbeans.modules.project.ui.actions.NewFile$2.run(NewFile.java:167)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1424)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1973)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.IllegalStateException: This method must be called in the event thread.
   at org.openide.util.RequestProcessor.post(RequestProcessor.java:425)
   at org.netbeans.modules.project.ui.actions.NewFile.doPerform(NewFile.java:164)
   at org.netbeans.modules.project.ui.actions.NewFile.access$100(NewFile.java:95)
   at org.netbeans.modules.project.ui.actions.NewFile$PopupListener.actionPerformed(NewFile.java:369)
   at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
   at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
   at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
   at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
   at javax.swing.AbstractButton.doClick(AbstractButton.java:357)
   at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:809)
   at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:850)
   at java.awt.Component.processMouseEvent(Component.java:6267)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
   at java.awt.Component.processEvent(Component.java:6032)
   at java.awt.Container.processEvent(Container.java:2041)
   at java.awt.Component.dispatchEventImpl(Component.java:4630)
   at java.awt.Container.dispatchEventImpl(Container.java:2099)
   at java.awt.Component.dispatchEvent(Component.java:4460)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4577)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4238)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4168)
   at java.awt.Container.dispatchEventImpl(Container.java:2085)
   at java.awt.Window.dispatchEventImpl(Window.java:2478)
   at java.awt.Component.dispatchEvent(Component.java:4460)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:153)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)