I did a restore of part of a site and now when I try to open any office documents I receive the Server Error in '/' Application runtime error message. I looked on the sharepoint server's event logs and there is an ASP.net 2.0 error message and it states:
Exception type: FileNotFoundException
Exception message: The site https://blahblah/_layouts/Error.aspx
could not be found in the Web application SPWebApplication Name=SharePoint - 443.