Server name or address could not be resolved

[organicg]

I'm having a problem with a solution in VS.NET. When I open the solution, I get:
"The web server reported the following error when attempting to create or open the web project located at

http://localhost/myapp.

The server name or address could not be resolved.
I tried adding ASPNET and IUSR_machine to Administrators group, but that didn't help.
If I click Application Settings-->Application Name--> REMOVE in IIS for my virtual directory, I can open the solution, but I have to CREATE the application name again before I can run the app.
I tried creating a new webapp in VS.NET and that works fine.
I'm ready to rebuild my solution from new.
Any ideas, thanks?

 

[organicg]

Oh...my...God. I can't believe that I ever figured this out, but since I was rebuilding the solution and got the same error, I kept backing up and it took me to web.config. I got the error if I opened the Solution while NOT connected to the internet because of this line:

    <customErrors mode="On" defaultRedirect="[URL unfurl="true"]http://www.realdomain.com/Error.aspx"[/URL]
    />