While creating your first page or while creating a custom web page in Microsoft Dynamics Ax 2012 or Microsoft Dynamics Ax 2009 Enterprise Portal , the un-handled exception error pops-up very often. A screenshot of the error is mentioned below.
1. This issue arises because the debugging option is disabled in the web.config file. This is an issue which we commonly face while developing ASP.NET applications.
2. Irrespective of whether the Enterprise Portal site collection is hosted on port 80 or a non-port 80 site, the web.config file is generated for every website that is hosted on the Internet Information Services (IIS) Web server role of Windows Server 2012/Windows Server 2012 R2/Windows Server 2008 R2/Windows Server 2008.
Ensure that the debug property on the tag is set to true in the web.config file. This will resolve the problem of unhandled exception.
The default location for a web.config file is: <%systemdrive%>\inetpub\wwwroot\wss\VirtualDirectories\\web.config