ParametersInterceptor – [setParameters]: Unexpected Exception caught setting FIELDNAME on CLASSNAME
This exception occurs if you have missed getters and setters for your class variable.
This warning is generated since you have specified formName.action in action attribute of form.You get get rid of those by changing the action attribute to formName instead of formName.action
Reason for Error
<s:form action="Reports.action" method="post">
Change it To
<s:form action="Reports" method="post" namespace="/">