In Dynamics AX 4.0 when you are browsing for an Enterprise Portal page you might get a blank or half blank page. So instead of your Menus, Web Forms and WebLets with data you only receive a white background with no or only some content.

A blank Enterprise Portal page is an indicator that something unplanned has happened, most often an unhandled X++ exception.

As in Dynamics AX 4.0 the generation of the Web Form's and the WebLet's HTML code is also happening in X++ any unhandled X++ exception can interrupt the HTML code generation. This can effect not only the current Web Form / WebLet but also the other Web Forms / WebLets on the same page, depending on the method that is currently executed when the exception is raised.

Side note:
An unhandled X++ exception is an exception that is raised but not cached in a try-catch block.

When you are running into a blank Enterprise Portal page or have a Web Form that does not show up usually the Application event log contains information about the reason. If you place for example the X++ code throw error('This exception is raised by intention!'); in a Web Form method the following events will be written to the event log:

Microsoft Dynamics Business Connector Session #.

An X++ exception has occurred.
This exception is raised by intention!

and:

The Microsoft Dynamics session get object call runWebletItem failed.

This exception is raised by intention!

Microsoft.Dynamics.BusinessConnectorNet.XppException
   at Microsoft.Dynamics.BusinessConnectorNet.AxaptaObject.Call(String methodName, Object[] paramList)
   at Microsoft.Dynamics.WebParts.SessionItem.AxaptaObjectImpl.Microsoft.Dynamics.WebParts.IAxaptaObject.Call(String methodname, Object[] paramlist)
 

You can of course also use the Dynamics AX Debugger to locate the cause of the exception. If you never have debugged Enterprise Portal content before, the following articles are a good start:

--author: Alexander Lachner
--editor: Alexander Lachner
--date: 28/07/2009