How to resolve IllegalStateException: Failed to load ApplicationContext
<p>This is the error message that I get when executing my spring boot app:</p>

<pre><code>java.lang.IllegalStateException: Failed to load ApplicationContext

    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)
    at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83)
    at org.springframework.boot.test.autoconfigure.AutoConfigureReportTestExecutionListener.prepareTestInstance(AutoConfigureReportTestExecutionListener.java:49)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:119)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:42)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:234)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:74)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
Caused by: org.springframework.beans.factory.BeanDefinitionStoreException: Unexpected exception parsing XML document from class path resource [elasticsearch-template-test.xml]; nested exception is java.lang.NoClassDefFoundError: org/w3c/dom/ElementTraversal
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:414)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:336)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:304)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:181)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:217)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:188)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:252)
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadBeanDefinitions(AbstractGenericContextLoader.java:257)
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:124)
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:60)
    at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.delegateLoading(AbstractDelegatingSmartContextLoader.java:108)
    at org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.loadContext(AbstractDelegatingSmartContextLoader.java:251)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:98)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:116)
    ... 28 more
Caused by: java.lang.NoClassDefFoundError: org/w3c/dom/ElementTraversal
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at org.apache.xerces.parsers.AbstractDOMParser.startDocument(Unknown Source)
    at org.apache.xerces.impl.xs.XMLSchemaValidator.startDocument(Unknown Source)
    at org.apache.xerces.impl.dtd.XMLDTDValidator.startDocument(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentScannerImpl.startEntity(Unknown Source)
    at org.apache.xerces.impl.XMLVersionDetector.startDocumentParsing(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
    at org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
    at org.apache.xerces.jaxp.DocumentBuilderImpl.parse(Unknown Source)
    at org.springframework.beans.factory.xml.DefaultDocumentLoader.loadDocument(DefaultDocumentLoader.java:76)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadDocument(XmlBeanDefinitionReader.java:429)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:391)
    ... 41 more
Caused by: java.lang.ClassNotFoundException: org.w3c.dom.ElementTraversal
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 66 more
</code></pre>

<p>This error started appearing after adding new dependency to <code>pom.xml</code> and adding new classes to the project.
What is the origin of this issue? Some problem with <code>pom.xml</code> or any problem with classes? As far as I understand from the message there is something wrong with XML parser, but I haven't deleted anything from <code>pom.xml</code>.</p>

<p>This is my <code>pom.xml</code>:</p>

<pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
&lt;project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
    &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;

    &lt;groupId&gt;org.myapp&lt;/groupId&gt;
    &lt;artifactId&gt;myapi&lt;/artifactId&gt;
    &lt;packaging&gt;jar&lt;/packaging&gt;
    &lt;version&gt;1.0-SNAPSHOT&lt;/version&gt;

    &lt;parent&gt;
        &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
        &lt;artifactId&gt;spring-boot-starter-parent&lt;/artifactId&gt;
        &lt;version&gt;1.4.0.BUILD-SNAPSHOT&lt;/version&gt;
    &lt;/parent&gt;

    &lt;dependencies&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
            &lt;artifactId&gt;spring-boot-starter-web&lt;/artifactId&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
            &lt;artifactId&gt;spring-boot-starter-test&lt;/artifactId&gt;
            &lt;scope&gt;test&lt;/scope&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;org.springframework.data&lt;/groupId&gt;
            &lt;artifactId&gt;spring-data-elasticsearch&lt;/artifactId&gt;
            &lt;version&gt;2.0.0.RELEASE&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;com.jayway.jsonpath&lt;/groupId&gt;
            &lt;artifactId&gt;json-path&lt;/artifactId&gt;
            &lt;scope&gt;test&lt;/scope&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;commons-lang&lt;/groupId&gt;
            &lt;artifactId&gt;commons-lang&lt;/artifactId&gt;
            &lt;version&gt;2.4&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;org.elasticsearch&lt;/groupId&gt;
            &lt;artifactId&gt;elasticsearch&lt;/artifactId&gt;
            &lt;version&gt;${es.version}&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;org.apache.poi&lt;/groupId&gt;
            &lt;artifactId&gt;poi&lt;/artifactId&gt;
            &lt;version&gt;3.9&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;org.slf4j&lt;/groupId&gt;
            &lt;artifactId&gt;slf4j-api&lt;/artifactId&gt;
            &lt;version&gt;1.7.2&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;org.slf4j&lt;/groupId&gt;
            &lt;artifactId&gt;slf4j-log4j12&lt;/artifactId&gt;
            &lt;version&gt;1.7.2&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;org.apache.poi&lt;/groupId&gt;
            &lt;artifactId&gt;poi-ooxml&lt;/artifactId&gt;
            &lt;version&gt;3.9&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;commons-io&lt;/groupId&gt;
            &lt;artifactId&gt;commons-io&lt;/artifactId&gt;
            &lt;version&gt;2.4&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;net.sf.opencsv&lt;/groupId&gt;
            &lt;artifactId&gt;opencsv&lt;/artifactId&gt;
            &lt;version&gt;2.3&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;org.apache.hadoop&lt;/groupId&gt;
            &lt;artifactId&gt;hadoop-client&lt;/artifactId&gt;
            &lt;version&gt;2.5.1&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;joda-time&lt;/groupId&gt;
            &lt;artifactId&gt;joda-time&lt;/artifactId&gt;
            &lt;version&gt;2.9.3&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;junit&lt;/groupId&gt;
            &lt;artifactId&gt;junit&lt;/artifactId&gt;
            &lt;version&gt;4.12&lt;/version&gt;
            &lt;scope&gt;test&lt;/scope&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;org.apache.jena&lt;/groupId&gt;
            &lt;artifactId&gt;jena-tdb&lt;/artifactId&gt;
            &lt;version&gt;3.0.0&lt;/version&gt;
            &lt;scope&gt;compile&lt;/scope&gt;
        &lt;/dependency&gt;
        &lt;!--&lt;dependency&gt;--&gt;
            &lt;!--&lt;groupId&gt;org.json&lt;/groupId&gt;--&gt;
            &lt;!--&lt;artifactId&gt;json&lt;/artifactId&gt;--&gt;
            &lt;!--&lt;version&gt;20151123&lt;/version&gt;--&gt;
            &lt;!--&lt;scope&gt;compile&lt;/scope&gt;--&gt;
        &lt;!--&lt;/dependency&gt;--&gt;
    &lt;/dependencies&gt;

    &lt;properties&gt;
        &lt;java.version&gt;1.8&lt;/java.version&gt;
        &lt;es.version&gt;2.1.0&lt;/es.version&gt;
        &lt;start-class&gt;org.myapp.api.Application&lt;/start-class&gt;
    &lt;/properties&gt;


    &lt;build&gt;
        &lt;plugins&gt;
            &lt;plugin&gt;
                &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
                &lt;artifactId&gt;spring-boot-maven-plugin&lt;/artifactId&gt;
                &lt;version&gt;1.3.3.RELEASE&lt;/version&gt;
            &lt;/plugin&gt;
        &lt;/plugins&gt;
    &lt;/build&gt;

    &lt;repositories&gt;
        &lt;repository&gt;
            &lt;id&gt;spring-releases&lt;/id&gt;
            &lt;url&gt;https://repo.spring.io/libs-release&lt;/url&gt;
        &lt;/repository&gt;
        &lt;repository&gt;
            &lt;id&gt;spring-snapshots&lt;/id&gt;
            &lt;name&gt;Spring Snapshots&lt;/name&gt;
            &lt;url&gt;https://repo.spring.io/libs-snapshot&lt;/url&gt;
            &lt;snapshots&gt;
                &lt;enabled&gt;true&lt;/enabled&gt;
            &lt;/snapshots&gt;
        &lt;/repository&gt;
    &lt;/repositories&gt;
    &lt;pluginRepositories&gt;
        &lt;pluginRepository&gt;
            &lt;id&gt;spring-releases&lt;/id&gt;
            &lt;url&gt;https://repo.spring.io/libs-release&lt;/url&gt;
        &lt;/pluginRepository&gt;
    &lt;/pluginRepositories&gt;
</code></pre>

<p>And my xml file is the following:</p>

<pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
&lt;beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:elasticsearch="http://www.springframework.org/schema/data/elasticsearch"
       xsi:schemaLocation="http://www.springframework.org/schema/data/elasticsearch http://www.springframework.org/schema/data/elasticsearch/spring-elasticsearch.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"&gt;

    &lt;elasticsearch:node-client id="client" local="true" cluster-name="#{T(java.util.UUID).randomUUID().toString()}"
                               http-enabled="false" path-data="target/elasticsearchTestData" path-home="src/test/resources/test-home-dir"
                               path-configuration="node-client-configuration.yml"/&gt;

&lt;/beans&gt;
</code></pre>