Erro após addActionError() Struts 2

Fala galera,

tenho um formulário com alguns campos, quando não passa na validação feita na action e adiciono mensagem de erro via addActionError() mensagem de erro aparece normalmente e retorna para a página especificada no struts.xml o problema ocorre quando eu tento fazer um novo submit, ocorre um erro inesperado conforme mostra a seguir:

Ocorreu um erro interno. Tente novamente em alguns minutos.

Caso o erro persista, favor entrar em contato com o analista responsável e informar o código do erro: "exception.requestId".

Mensagem:

No result defined for action br.com.bradseg.siad.imagemanalisedocumento.hphm.anexararquivo.action.AnexarArquivoAction$$EnhancerByCGLIB$$7d557a3c and result input

Stacktrace:

No result defined for action br.com.bradseg.siad.imagemanalisedocumento.hphm.anexararquivo.action.AnexarArquivoAction$$EnhancerByCGLIB$$7d557a3c and result input
at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:375)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:277)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:263)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:207)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:270)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:190)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at br.com.bradseg.bsad.framework.web.struts.support.RedirectMessageInterceptor.intercept(RedirectMessageInterceptor.java:34)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:498)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
at org.apache.struts2.dispatcher.ng.filter.StrutsExecuteFilter.doFilter(StrutsExecuteFilter.java:88)
at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:188)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:116)
at com.opensymphony.sitemesh.webapp.SiteMeshFilter.obtainContent(SiteMeshFilter.java:129)
at com.opensymphony.sitemesh.webapp.SiteMeshFilter.doFilter(SiteMeshFilter.java:77)
at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:188)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:116)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareFilter.doFilter(StrutsPrepareFilter.java:82)
at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:188)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:116)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:83)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:188)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:116)
at ch.qos.logback.classic.helpers.MDCInsertingServletFilter.doFilter(MDCInsertingServletFilter.java:51)
at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:188)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:116)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain._doFilter(WebAppFilterChain.java:77)
at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:908)
at com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:997)
at com.ibm.ws.webcontainer.extension.DefaultExtensionProcessor.invokeFilters(DefaultExtensionProcessor.java:1062)
at com.ibm.ws.webcontainer.extension.DefaultExtensionProcessor.handleRequest(DefaultExtensionProcessor.java:982)
at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:3935)
at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:276)
at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:931)
at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1592)
at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:186)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:452)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:511)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:305)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.ready(HttpInboundLink.java:276)
at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.sendToDiscriminators(NewConnectionInitialReadCallback.java:214)
at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.complete(NewConnectionInitialReadCallback.java:113)
at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165)
at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138)
at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204)
at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775)
at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1613)

=============================== // ===============================

Minha jsp:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><%@page
	language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
<body>
	<script type="text/javascript" src="<s:url value='/includes/js/anexarArquivo.js'/>"></script>

	<div class="main">

               
	       <s:if test="hasActionErrors()">
	              <s:iterator value="actionErrors">
				<div id="errorMessages" class="error">
					<s:property />
				</div>
			</s:iterator>
	       </s:if>

		<span class="titulo">Anexar Arquivos</span>
		<br /><br /><br />
		
		<s:form action="anexarHm" method="POST" enctype="multipart/form-data">
			<table class="tabela_interna" width="100%">
				<tbody>
					<tr>
						<td width="250px" class="td_label"><label>N&uacute;mero do Protocolo:</label><span class="obrigatorio">*</span></td>
						<td class="td_dados"><s:textfield id="numProtocolo" name="anexarArquivoDTO.numProtocolo" maxlength="12" cssClass="field_numeric"/></td>
					</tr>
					<tr>
						<td class="td_label"><label>N&uacute;mero da Guia:</label><span class="obrigatorio">*</span></td>
						<td class="td_dados"><s:textfield id="numGuia" name="anexarArquivoDTO.numGuia" maxlength="20" cssClass="field_numeric"/></td>
					</tr>
					<tr>
						<td class="td_label"><label>Senha:</label><span class="obrigatorio">*</span></td>
						<td class="td_dados"><s:textfield id="senha" name="anexarArquivoDTO.senha" maxlength="10" cssClass="field_alfa"/></td>
					</tr>
					<tr>
						<td class="td_label"><label>Tipo Documento:</label><span class="obrigatorio">*</span></td>
						<td class="td_dados">
							<s:select id="tipoDocumento"
								value="anexarArquivoDTO.tipoDocumento"
								name="anexarArquivoDTO.tipoDocumento"
								headerKey=""
								headerValue="Selecione"
								list="#{'1':'Guia de Solicitação de Internação',
									    '2':'Fatura do Prestador',
									    '3':'Relatório Médico',
									    '4':'Notas Fiscais',
									    '5':'RAH Manual',
									    '6':'Folha de Sala Cirúrgica',
									    '7':'Solicitação de OPME',
									    '8':'Laudo Imagem',
									    '9':'Outros'}"/>
						</td>
					</tr>	
					<tr>
						<td class="td_label"><label>Arquivo:</label><span class="obrigatorio">*</span></td>
						<td class="td_dados"><s:file id="anexo" name="anexarArquivoDTO.arquivo" size="80" /></td>
					</tr>
				</tbody>
			</table>
			<div align="left"><span class="obrigatorio">Os campos marcados com * são obrigatórios.</span></div>	
			<br /><br />
			
			<div class="centralizado">
				<button type="submit" style="width: 80px">Anexar</button>
			</div>
			<br /><br />
		</s:form>

		
		<s:if test="%{!listaAnexarArquivoDTO.isEmpty()}">
			<table width="100%" class="tabela_resultado">
				<thead>
					<tr>
						<td class="cabecalhoColuna" width="60%"><label>Arquivos</label></td>
						<td class="cabecalhoColuna" width="30%"><label>Tipo Documento</label></td>
						<td class="cabecalhoColuna" width="10%"><label>A&ccedil;&otilde;es</label></td>
					</tr>
				</thead>
				<tbody>
					<s:iterator value="listaAnexarArquivoDTO" var="anexo">
					<tr>
						<td class="colunaTabela direitaTexto"><s:property value="arquivoFileName"/></td>
						<td class="colunaTabela direitaTexto"><s:property value="tipoDocumento"/></td>
						<td class="colunaTabela centroTexto">
							<s:url id="excluir"	action="excluirAnexoHm.do">
								<s:param name="anexarArquivoDTO.arquivoFileName" value="arquivoFileName"/>
							</s:url>
							
							<s:a href="%{excluir}" method="POST"
							   name='linkAcao' 
							   title="Clique para excluir o anexo.">
								<img src="<s:url value="/includes/css/images/exclude.jpg"/>" width="18" height="18"/>
							</s:a>
							
						</td>
					</tr>	
					</s:iterator>		
				</tbody>
			</table>
			
			<br /><br />
			<s:form action="enviarAnexoHm" method="post">
				<div class="centralizado">
					<s:submit  type="button" cssStyle="width: 80px">Enviar</s:submit>
				</div>
			</s:form>
		</s:if>
	</div>

</body>
</html>

Minha Action:


@Controller
@Scope("session")
public class AnexarArquivoAction extends ActionSupport {

	private AnexarArquivoDTO anexarArquivoDTO;

	private List<AnexarArquivoDTO> listaAnexarArquivoDTO;

	public String anexarHm() {
		String retorno = Action.SUCCESS;
		try {
			if (this.validarAnexarHm()) {
				this.getListaAnexarArquivoDTO().add(anexarArquivoDTO.copy());
				anexarArquivoDTO = new AnexarArquivoDTO();
				addActionMessage(getText("msg.sucesso.anexar.arquivo.inclusao"));

			} else {
				retorno = Action.INPUT;
			}
		} catch (Exception e) {
			LOGGER.error("Erro ao anexar:", e);
			addActionError(getText("msg.erro.anexar.arquivo"));
			retorno = Action.ERROR;
		}
		return retorno;
	}

        private boolean validarAnexarHm() {
		boolean retorno = true;
		if (null != this.getAnexarArquivoDTO()) {
			/*validacao de campos obrigatorios*/
			if (!validarCamposObrigatoriosHm()) {
				addActionError(getText("msg.erro.global.campos.obrigatorios.nao.preenchidos"));
				retorno = false;
			}
		}
		return retorno;
	}

        // seters e getters

struts.xml:

      <package name="anexararquivo" namespace="/anexararquivo" extends="bsad-default">
		<action name="anexarHm" class="anexarArquivoAction" method="anexarHm">
			<result name="success">/WEB-INF/pages/pt_BR/anexararquivo/anexararquivo_hm.jsp</result>
			<result name="input">/WEB-INF/pages/pt_BR/anexararquivo/anexararquivo_hm.jsp</result>
		</action>
	</package>

Esse problema só ocorre quando eu adiciono mensagem de erro, se for mensagem de sucesso ou se não tiver mensagem nenhuma continua funcionando normalmente.

Agradeço desde já.