error while cleaning and building javafx app in netbeans, XML document structures must start and end within the same entity

Question

I'm new to xml, and trying to deploy my javafx program, getting to run and clean I've got the following error, and couldn't find any answer regarding the solution thereof, so would appreciate if you helped me:

F:\\IT\\PROGRAMMING\\LJPROJECTS\\MyShutDownTheCompProgram\\build.xml:67: XML document structures must start and end within the same entity.

The xml code goes as follows:

<?xml version="1.0" encoding="UTF-8"?><!-- You may freely edit this file. See commented blocks below for --><!-- some examples of how to customize the build. --><!-- (If you delete it and reopen the project it will be recreated.) --><!-- By default, only the Clean and Build commands use this build script. --><project name="MyShutDownTheCompProgram" default="default" basedir="." xmlns:fx="javafx:com.sun.javafx.tools.ant">
    <description>Builds, tests, and runs the project MyShutDownTheCompProgram.</description>
    <import file="nbproject/build-impl.xml"/>
    <!--

    There exist several targets which are by default empty and which can be 
    used for execution of your tasks. These targets are usually executed 
    before and after some main targets. Those of them relevant for JavaFX project are: 

      -pre-init:                 called before initialization of project properties
      -post-init:                called after initialization of project properties
      -pre-compile:              called before javac compilation
      -post-compile:             called after javac compilation
      -pre-compile-test:         called before javac compilation of JUnit tests
      -post-compile-test:        called after javac compilation of JUnit tests
      -pre-jfx-jar:              called before FX SDK specific <fx:jar> task
      -post-jfx-jar:             called after FX SDK specific <fx:jar> task
      -pre-jfx-deploy:           called before FX SDK specific <fx:deploy> task
      -post-jfx-deploy:          called after FX SDK specific <fx:deploy> task
      -pre-jfx-native:           called just after -pre-jfx-deploy if <fx:deploy> runs in native packaging mode
      -post-jfx-native:          called just after -post-jfx-deploy if <fx:deploy> runs in native packaging mode
      -post-clean:               called after cleaning build products

    (Targets beginning with '-' are not intended to be called on their own.)

    Example of inserting a HTML postprocessor after javaFX SDK deployment:

        <target name="-post-jfx-deploy">
            <basename property="jfx.deployment.base" file="${jfx.deployment.jar}" suffix=".jar"/>
            <property name="jfx.deployment.html" location="${jfx.deployment.dir}${file.separator}${jfx.deployment.base}.html"/>
            <custompostprocess>
                <fileset dir="${jfx.deployment.html}"/>
            </custompostprocess>
        </target>

    Example of calling an Ant task from JavaFX SDK. Note that access to JavaFX SDK Ant tasks must be
    initialized; to ensure this is done add the dependence on -check-jfx-sdk-version target:

        <target name="-post-jfx-jar" depends="-check-jfx-sdk-version">
            <echo message="Calling jar task from JavaFX SDK"/>
            <fx:jar ...>
                ...
            </fx:jar>
        </target>

    For more details about JavaFX SDK Ant tasks go to
    http://docs.oracle.com/javafx/2/deployment/jfxpub-deployment.htm

    For list of available properties check the files
    nbproject/build-impl.xml and nbproject/jfx-impl.xml.

    -->

<target name="-post-jfx-deploy">
       <fx:deploy width="${javafx.run.width}" height="${javafx.run.height}" 
                  nativeBundles="all"
                  outdir="${basedir}/${dist.dir}" outfile="${application.title}">
          <fx:application name="${application.title}" 
                          mainClass="${javafx.main.class}"/>
          <fx:resources>
              <fx:fileset dir="${basedir}/${dist.dir}"
                          includes="*.jar"/>
          </fx:resources>
          <fx:info title="${application.title}" 
                   vendor="${application.vendor}"/>
        </fx:deploy>          
     </target>

Answer 1

You must have to end the tags you started before. You have to use </project> at end of your XML file.

Answer 2

Open build.xml file from your Files tab. Usually there put two tags with the same name, and does the same job.The first one is <build> and the second is <defend> you should delete these extra two tags.