Struts Error - org.apache.jasper.JasperException: Module 'null' not found.

For an exception like this -

org.apache.jasper.JasperException: Module 'null' not found.
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:370)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:362)


root cause

java.lang.NullPointerException: Module 'null' not found.
org.apache.struts.taglib.TagUtils.getModuleConfig(TagUtils.java:743)
org.apache.struts.taglib.TagUtils.getModuleConfig(TagUtils.java:723)
org.apache.struts.taglib.html.FormTag.lookup(FormTag.java:742)
org.apache.struts.taglib.html.FormTag.doStartTag(FormTag.java:417)
org.apache.jsp.insert_jsp._jspx_meth_html_form_0(insert_jsp.java:107)
org.apache.jsp.insert_jsp._jspService(insert_jsp.java:83)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:362)

Specify <\load-on-startup>2<\load-on-startup> in the stanza that defines the Struts ActionServlet in your web.xml file because that's the problem. If you did specified that, there may be some other problem that is preventing the Struts ActionServlet from loading properly when the server first starts up. Look at the logs created when the server is first starting and see if there are any errors related to Struts.