Step to reproduce:
1. Open attached project
2. Right-click on project node and choose property
3. Click Ok button in Property dialog

Exception detail:
java.lang.AssertionError: cvc-complex-type.2.4.a: Invalid content was found starting with element 'acction'. One of '{"http://www.netbeans.org/ns/freeform-project/2":action}' is expected.; rejected content: <general-data xmlns="http://www.netbeans.org/ns/freeform-project/2">
    <!-- Do not use Project Properties customizer when editing this file manually. -->
    <name>Tomcat 6.0</name>
    <properties>
        <property name="ant.script">/nbproject/nb-build-helper.xml.xml</property>
    </properties>
    <folders>
        <source-folder>
            <label>java</label>
            <type>java</type>
            <location>java</location>
            <excludes>org/apache/tomcat/util/net/puretls/</excludes>
            <encoding>UTF-8</encoding>
        </source-folder>
    </folders>
    <ide-actions>
        <action name="build">
            <script>${ant.script}</script>
            <target>build</target>
        </action>
        <action name="clean">
            <script>${ant.script}</script>
            <target>clean_all</target>
        </action>
        <action name="javadoc">
            <script>dist.xml</script>
            <target>dist-prepare</target>
            <target>dist-source</target>
            <target>dist-javadoc</target>
        </action>
        <action name="rebuild">
            <target>clean</target>
            <target>deploy</target>
        </action>
        <acction name="start">
            <script>${ant.script}</script>
            <target>Start</target>
        </acction>
    </ide-actions>
    <view>
        <items>
            <source-folder style="packages">
                <label>java</label>
                <location>java</location>
                <excludes>org/apache/tomcat/util/net/puretls/</excludes>
            </source-folder>
            <source-file>
                <location>build.xml</location>
            </source-file>
        </items>
        <context-menu>
            <ide-action name="build"/>
            <ide-action name="clean"/>
            <ide-action name="javadoc"/>
            <ide-action name="rebuild"/>
            <ide-action name="start"/>
        </context-menu>
    </view>
    <subprojects/>
</general-data>

	at org.netbeans.modules.ant.freeform.spi.support.Util$2.run(Util.java:348)
	at org.netbeans.modules.ant.freeform.spi.support.Util$2.run(Util.java:338)
	at org.openide.util.Mutex.writeAccess(Mutex.java:321)
	at org.netbeans.modules.ant.freeform.spi.support.Util.putPrimaryConfigurationData(Util.java:337)
	at org.netbeans.modules.java.freeform.JavaProjectGenerator.putSourceFolders(JavaProjectGenerator.java:212)
	at org.netbeans.modules.java.freeform.ui.ProjectModel$2.run(ProjectModel.java:180)
	at org.netbeans.modules.java.freeform.ui.ProjectModel$2.run(ProjectModel.java:178)
	at org.openide.util.Mutex.writeAccess(Mutex.java:321)
	at org.netbeans.modules.java.freeform.ui.ProjectModel.saveProject(ProjectModel.java:177)
	at org.netbeans.modules.java.freeform.ui.SourceFoldersCategoryProvider$1.actionPerformed(SourceFoldersCategoryProvider.java:65)
	at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener.actionPerformed(CustomizerDialog.java:207)
	at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener.access$200(CustomizerDialog.java:159)
	at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener$1.run(CustomizerDialog.java:183)
	at org.openide.util.Mutex.writeAccess(Mutex.java:321)
	at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener.actionPerformed(CustomizerDialog.java:180)
	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:3260)
	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(Container.java:4322)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.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)
[catch] at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
	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)