Sharepoint ?wsdl does not return WSDL file, returns the normal page instead

my SharePoint problem is fixed, here are the details.

1. Run "SharePoint Product Technologies Configuration Wizard"
   1.1. Select do not disconnect from this server farm, click next
   1.2. Select No, this machine will continue to host the web site, click next.
   1.3 Click Next
2. Restart IIS

As it turns out, the problem was mixing two technologies. wdsl.exe belongs to the older "Web References" that predate WCF. The newer tool svcutil.exe is meant for generating WCF "Service Reference" interfaces.

So what happened was that WCF looked for [ServiceContract] and [OperationContract] attributes. When it couldn't find any, it silently did nothing.

The silent suppression of this condition is annoying, to say the least. An error like No service with [ServiceContract] attribute found would really have helped.

Note that you can manually add [ServiceContract], but that will leave you with half "Service Reference" half "Web Reference". The result probably will not work.