The ReportManager web UI for SSRS is just Asp.Net Forms. So you have the usual options. For example:
You can use web.config and setup the
customErrors tag to handle the appropriate uncaught exceptions in the ReportManager application.
Additionally, you could do what I did: Create your own
IHttpModule and use the
Init(HttpApplication context) method to hookup your own
EventHandler to the
HttpContext.Error event. From there, you can capture the underlying exception, decide what to do about it, and generate your own nice message. You could even go so far as to do a
Server.Transfer to a custom .aspx page to make it easier to craft a nice message---instead of embedding your Html directly in your code.
This approach works in SSRS 2008 as well as SSRS 2012.