The specified node was not found in the web.config file

Failed to apply a web.config modification to file 'configuration/system.web/pages'.  The specified node "C:\Inetpub\wwwroot\wss\VirtualDirectories\80\web.config" was not found in the web.config file.

This happens on our dev farm and our production farm. The feature is not activated. If I go into web application features and try to activate it, I still get the same error message.