Soap:ServerServer was unable to process request. => Value does not fall within the expected range.

ProblemWhile editing SP 2010 website using the SPD 2010.

Error
The Server Could not complete your request. Fore More information click the details button
soap:ServerServer was unable to process request. => Value does not fall within the expected range.

Cause
I think - It's might be related to DNS name resolution...

Workaround
Use FQDN (Fully Qualified Domain Name) instead of "localhost"

ex: http//myserver:80/Default.aspx