title: How to fix javax.servlet.ServletException: BeanUtils.populate
body: <p>My app is on a digital ocean server with ubuntu Ubuntu 14.04.1 LTS (GNU/Linux 3.13.0-43-generic x86_64)</p>
  
  <p>when I run java -version i get this output:</p>
  
  <pre><code>java version "1.8.0_31"
  Java(TM) SE Runtime Environment (build 1.8.0_31-b13)
  Java HotSpot(TM) 64-Bit Server VM (build 25.31-b07, mixed mode)
  </code></pre>
  
  <p>I'm using struts 2 and i've installed tomcat 8.0.18 to deploy it.</p>
  
  <p>Almost everything is fine with my app, except that when I click on a button that saves some specific information from a form i got this error</p>
  
  <pre><code>javax.servlet.ServletException: javax.servlet.ServletException: BeanUtils.populate
  org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:286)
  org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
  org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
  org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
  </code></pre>
  
  <p>Also the root cause is this (just as the same error show at the bottom)</p>
  
  <pre><code>java.lang.IllegalArgumentException: No Index Value
  org.apache.commons.beanutils.expression.DefaultResolver.getIndex(DefaultResolver.java:94)
  org.apache.commons.beanutils.BeanUtilsBean.setProperty(BeanUtilsBean.java:917)
  org.apache.commons.beanutils.BeanUtilsBean.populate(BeanUtilsBean.java:830)
  org.apache.commons.beanutils.BeanUtils.populate(BeanUtils.java:433)
  org.apache.struts.util.RequestUtils.populate(RequestUtils.java:467)
  org.apache.struts.chain.commands.servlet.PopulateActionForm.populate(PopulateActionForm.java:50)
  org.apache.struts.chain.commands.AbstractPopulateActionForm.execute(AbstractPopulateActionForm.java:60)
  org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
  org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
  org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:304)
  org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
  org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
  org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
  org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
  org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
  </code></pre>
  
  <p><strong>weird thing</strong></p>
  
  <p>When i deploy the same app on a windows machine it runs perfectly fine, everything works! When I use a unix (ubuntu 14.04, ubuntu 14.10, fedora 21) it just doesn't work and i got the error above.</p>
  
  <p>¿How can i fix it? 
  Many thanks!</p>
  
  <p>Sorry if this is a noob bug, i'm new on struts development </p>