If you’re getting the error in the subject line, and it seemed to come out of the blue, there might be a very easy fix to this.
Check your Views folder. If you have inadvertently deleted that web.config file, this error will definitely show up. If you are using either TFS or SourceSafe to store your code, then just find it there and put it back in the folder.
All Things DotNet Discussed – Winforms/ASP.Net/SharePoint/WPF