java.lang.IllegalStateException: Cannot generate build scripts from a modified project
        at org.netbeans.spi.project.support.ant.GeneratedFilesHelper$2.run(GeneratedFilesHelper.java:579)
        at org.netbeans.spi.project.support.ant.GeneratedFilesHelper$2.run(GeneratedFilesHelper.java:576)
        at org.openide.util.Mutex.readAccess(Mutex.java:327)
        at org.netbeans.spi.project.support.ant.GeneratedFilesHelper.getBuildScriptState(GeneratedFilesHelper.java:576)
        at org.netbeans.modules.java.j2seproject.ui.customizer.J2SEProjectProperties.save(J2SEProjectProperties.java:402)
        at org.netbeans.modules.java.j2seproject.ui.customizer.CustomizerProviderImpl$StoreListener.actionPerformed(CustomizerProviderImpl.java:160)
        at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener$2$1.run(CustomizerDialog.java:277)
        at org.openide.util.Mutex.writeAccess(Mutex.java:394)
        at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener$2.run(CustomizerDialog.java:273)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:576)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1013)
Caused: org.openide.util.RequestProcessor$Item: task failed: java.lang.IllegalStateException: Cannot generate build scripts from a modified project
        at org.openide.util.RequestProcessor$Item.fillInStackTrace(RequestProcessor.java:853)
        at java.lang.Throwable.<init>(Throwable.java:181)
        at java.lang.Exception.<init>(Exception.java:29)
        at org.openide.util.RequestProcessor$Item.<init>(RequestProcessor.java:819)
        at org.openide.util.RequestProcessor$Task.schedule(RequestProcessor.java:629)
        at org.openide.util.RequestProcessor.post(RequestProcessor.java:295)
        at org.openide.util.RequestProcessor.post(RequestProcessor.java:266)
        at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener.actionPerformed(CustomizerDialog.java:270)
        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.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
        at java.awt.Component.processMouseEvent(Component.java:6038)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
        at java.awt.Component.processEvent(Component.java:5803)
        at java.awt.Container.processEvent(Container.java:2058)
        at java.awt.Component.dispatchEventImpl(Component.java:4410)
        at java.awt.Container.dispatchEventImpl(Container.java:2116)
        at java.awt.Component.dispatchEvent(Component.java:4240)
        at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4322)
        at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:3986)
        at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:3916)
        at java.awt.Container.dispatchEventImpl(Container.java:2102)
        at java.awt.Window.dispatchEventImpl(Window.java:2429)
        at java.awt.Component.dispatchEvent(Component.java:4240)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)