問題と言うのは、Struts1.3.5に付属しているstruts-exeample.warを
サーバにデプロイした後アクセスすると、

18: <p>Each of these links lead to a separate "module" within this application.</p>
19:
20: <ul>
21: <li><html:link module="/exercise" action="/welcome">Taglib Test Pages</html:link></li>
22:
23: <li><html:link module="/upload" action="/upload">Upload examples</html:link></li>
24:


Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:506)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
sun.reflect.GeneratedMethodAccessor152.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:585)
org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:243)
java.security.AccessController.doPrivileged(Native Method)
javax.security.auth.Subject.doAsPrivileged(Subject.java:517)
org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:275)
org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:161)
java.security.AccessController.doPrivileged(Native Method)