title: java.lang.IllegalArgumentException: The main resource set specified [...] is not valid
body: <p>I'm having trouble starting my Tomcat server, it used to work, but I did something wrong and now it throws me this exception:</p>
  
  <pre><code>Caused by: java.lang.IllegalArgumentException: The main resource set specified [E:\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\workspace\j2eeapplication\target\j2eeapplication-0.0.1-SNAPSHOT] is not valid
      at org.apache.catalina.webresources.StandardRoot.startInternal(StandardRoot.java:643)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
      ... 9 more
  </code></pre>
  
  <p>And this is my web.xml :</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
          version="3.1"&gt;
  
          &lt;display-name&gt;J2EE Application Example&lt;/display-name&gt;
  
          &lt;welcome-file-list&gt;
                  &lt;welcome-file&gt;index.jsp&lt;/welcome-file&gt;
          &lt;/welcome-file-list&gt;
  
          &lt;context-param&gt;
                  &lt;param-name&gt;contextConfigLocation&lt;/param-name&gt;
                  &lt;param-value&gt;/WEB-INF/applicationContext.xml&lt;/param-value&gt;
          &lt;/context-param&gt;
  
          &lt;context-param&gt;
                  &lt;param-name&gt;javax.faces.DEFAULT_SUFFIX&lt;/param-name&gt;
                  &lt;param-value&gt;.xhtml&lt;/param-value&gt;
          &lt;/context-param&gt;
  
          &lt;context-param&gt;
                  &lt;param-name&gt;facelets.DEVELOPMENT&lt;/param-name&gt;
                  &lt;param-value&gt;true&lt;/param-value&gt;
          &lt;/context-param&gt;
  
          &lt;context-param&gt;
                  &lt;param-name&gt;javax.faces.FACELETS_REFRESH_PERIOD&lt;/param-name&gt;
                  &lt;param-value&gt;1&lt;/param-value&gt;
          &lt;/context-param&gt;
  
          &lt;listener&gt;
                  &lt;listener-class&gt;org.springframework.web.context.ContextLoaderListener&lt;/listener-class&gt;
          &lt;/listener&gt;
  
          &lt;servlet&gt;
                  &lt;servlet-name&gt;Resources Servlet&lt;/servlet-name&gt;
                  &lt;servlet-class&gt;org.springframework.js.resource.ResourceServlet&lt;/servlet-class&gt;
                  &lt;load-on-startup&gt;0&lt;/load-on-startup&gt;
          &lt;/servlet&gt;
  
          &lt;servlet-mapping&gt;
                  &lt;servlet-name&gt;Resources Servlet&lt;/servlet-name&gt;
                  &lt;url-pattern&gt;/resources/*&lt;/url-pattern&gt;
          &lt;/servlet-mapping&gt;
  
          &lt;servlet&gt;
                  &lt;servlet-name&gt;Spring MVC Dispatcher Servlet&lt;/servlet-name&gt;
                  &lt;servlet-class&gt;org.springframework.web.servlet.DispatcherServlet&lt;/servlet-class&gt;
                  &lt;init-param&gt;
                          &lt;param-name&gt;contextConfigLocation&lt;/param-name&gt;
                          &lt;param-value&gt;&lt;/param-value&gt;
                  &lt;/init-param&gt;
                  &lt;load-on-startup&gt;1&lt;/load-on-startup&gt;
          &lt;/servlet&gt;
  
          &lt;servlet-mapping&gt;
                  &lt;servlet-name&gt;Spring MVC Dispatcher Servlet&lt;/servlet-name&gt;
                  &lt;url-pattern&gt;/app/*&lt;/url-pattern&gt;
          &lt;/servlet-mapping&gt;
  
          &lt;servlet&gt;
                  &lt;servlet-name&gt;Faces Servlet&lt;/servlet-name&gt;
                  &lt;servlet-class&gt;javax.faces.webapp.FacesServlet&lt;/servlet-class&gt;
                  &lt;load-on-startup&gt;1&lt;/load-on-startup&gt;
          &lt;/servlet&gt;
  
          &lt;servlet-mapping&gt;
                  &lt;servlet-name&gt;Faces Servlet&lt;/servlet-name&gt;
                  &lt;url-pattern&gt;*.jsf&lt;/url-pattern&gt;
          &lt;/servlet-mapping&gt;
  
          &lt;filter&gt;
                  &lt;filter-name&gt;charEncodingFilter&lt;/filter-name&gt;
                  &lt;filter-class&gt;org.springframework.web.filter.CharacterEncodingFilter&lt;/filter-class&gt;
                  &lt;init-param&gt;
              &lt;param-name&gt;encoding&lt;/param-name&gt;
              &lt;param-value&gt;UTF-8&lt;/param-value&gt;
          &lt;/init-param&gt;
          &lt;init-param&gt;
              &lt;param-name&gt;forceEncoding&lt;/param-name&gt;
              &lt;param-value&gt;true&lt;/param-value&gt;
          &lt;/init-param&gt;
          &lt;/filter&gt;
  
          &lt;filter-mapping&gt;
              &lt;filter-name&gt;charEncodingFilter&lt;/filter-name&gt;
              &lt;url-pattern&gt;/*&lt;/url-pattern&gt;
          &lt;/filter-mapping&gt;
  
  &lt;/web-app&gt;
  </code></pre>
  
  <p>I looked at different solutions over the forums, but nothing worked. Final option will be uninstalling tomcat and fresh installation, cause I read that might work. Thanks for the help in advance.</p>