When I build an ASP.NET MVC application, I like to add my own error handler and serve up some nicer error messages to the users of the systems.  I allow for unknown exceptions to be emailed to me along with a stack trace so I can attempt to track them down and resolve unhandled issues.

Today I came across something new.  There were two different files that the client browsers from certain users were trying to access on the server.

- /_vti_bin/owssvr.dll
- /MSOffice/cltreq.asp

It appears that these are requests from a browser to look for web discussions on the site being accessed.  While this may be fine for a normal user’s browser, it is causing two exceptions to fire each time my application is being accessed.

To resolve this issue using ASP.NET MVC, I added the following code to the Global.asax.vb file at the beginning of the RegisterRoutes method:

routes.IgnoreRoute("_vti_bin/owssvr.dll")
routes.IgnoreRoute("MSOffice/cltreq.asp")