Configuration Error: Value cannot be null. Parameter name: type

Apr 5, 2011 at 2:51 PM

In my web.config file I have:
Line 91:         <clear />
Line 92:         <add name="MvcSiteMapProvider"
Line 93:              type="MvcSiteMapProvider.DefaultSiteMapProvider, MvcSiteMapProvider"
Line 94:              siteMapFile="~/Mvc.Sitemap"
Line 95:              securityTrimmingEnabled="true"

I have the sitemap provider dll in my project references but no luck.
But everytime I navigate to a page I get the following error:

Configuration Error

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: Value cannot be null.
Parameter name: type

Apr 7, 2011 at 9:52 AM

I worked it out, the visibilityprovider attribute in my node wasn't pointing to the correct assembly name.