HTTP Status 500 - type Exception report

Some times when I try to recive a PO I get the following error. Can you advise please

HTTP Status 500 -

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type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: BeanUtils.populate
org.apache.struts.util.RequestUtils.populate(RequestUtils.java:1254)
org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:821)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:254)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
com.adventnet.servicedesk.filter.EncodingFilter.doFilter(EncodingFilter.java:66)
com.adventnet.authentication.ContextChangeDetector.doFilter(ContextChangeDetector.java:100)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:75)

root cause

java.lang.IllegalArgumentException: Invalid mapped property 'CheckOfD630 Intel Core 2 Duo T7500 (2'
org.apache.commons.beanutils.PropertyUtils.getMappedProperty(PropertyUtils.java:546)
org.apache.commons.beanutils.PropertyUtils.getNestedProperty(PropertyUtils.java:750)
org.apache.commons.beanutils.PropertyUtils.getProperty(PropertyUtils.java:783)
org.apache.commons.beanutils.BeanUtils.setProperty(BeanUtils.java:793)
org.apache.commons.beanutils.BeanUtils.populate(BeanUtils.java:726)
org.apache.struts.util.RequestUtils.populate(RequestUtils.java:1252)
org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:821)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:254)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
com.adventnet.servicedesk.filter.EncodingFilter.doFilter(EncodingFilter.java:66)
com.adventnet.authentication.ContextChangeDetector.doFilter(ContextChangeDetector.java:100)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:75)

note The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.