Hi Sergey
The following snippet should make the error message visible
<ui:include src="messages.xhtml"/>
<h:messages errorClass="error" layout="table" style="width: 100%"/>

It works in almost all cases except in this particular case.

Please note <h:message> belongs to textfield , the onblur event of which loads remaining fields on form which are under <a4j:outputPanel>

I have added ajaxRendered="true" to it but it didnt made any difference

<h:inputText id="propertyTag" value="#{deviceBean.tagNumber}" >
 <a4j:support action="#{deviceBean.loadAssetDetails}" event="onblur" reRender="mypanel" />
 </h:inputText>
 <h:message for="propertyTag" styleClass="errorMessage" />

<a4j:outputPanel id="mypanel" ajaxRendered="true" >

 <h:panelGrid columns="3" styleClass="detail" columnClasses="label" >
 <h:outputLabel><h:outputText value="Model" /> </h:outputLabel>
 <h:inputText id="model" value="#{deviceBean.device.model}" disabled="#{deviceBean.disableMode}"/>
 <h:message for="model" styleClass="errorMessage" />
 </h:panelGrid>
</a4j:outputPanel>

public String loadAssetDetails() {
try{
 namsAsset = deviceManager.getAssetDetails(sourceSystem, tagNumber);
 }catch(RuntimeException re){

 if (re.getMessage().contains("No Asset found")){
 System.out.println("Inside Bean No Asset Exception");

 FacesUtils.addErrorMessage("errors.NoAsset", sourceSystem, tagNumber);

 return null;
 }

public static void addErrorMessage(String key, String arg1, String arg2) {
 //FacesContext.getCurrentInstance().addMessage(clientId, new FacesMessage(FacesMessage.SEVERITY_ERROR, msg, msg));
 ApplicationFactory factory =
 (ApplicationFactory) FactoryFinder.getFactory(FactoryFinder.APPLICATION_FACTORY);
 String bundleName = factory.getApplication().getMessageBundle();

 ResourceBundle messages = ResourceBundle.getBundle(bundleName);


 MessageFormat form = new MessageFormat(messages.getString(key));

 String msg = form.format(new Object[] { arg1, arg2 });



 System.out.println("Inside Error Message="+msg);
 FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_ERROR, msg, msg));


 }

Sergey
<h:messages> is there on the top of the xhtml page to print global messages. Here is the snippet

<ui:include src="messages.xhtml"/>
<h:messages errorClass="error" layout="table" style="width: 100%"/>