Resolving a HTTP/1.1 200 OK Server: Microsoft-IIS/7.5 Error with a SharePoint 2010 Web Application

This error stopped me in my tracks for a couple of hours, while just editing IIS bindings and Alternate Access Mappings my site stopped responding entirely.

Instead of displaying a lovely site, my browser just displayed a blank error message.   Turning off Friendly Error messages I found the following error message displayed :

HTTP/1.1 200 OK Server: Microsoft-IIS/7.5 Date: Tue, 10 Aug 2010 03:19:45 GMT Connection: close

Unfortunately this error is not as helpful as you would think.  The only time I’ve seen similar errors with SharePoint were with 404 errors, usually because a Web Application existed, but a Site Collection did not.

I also noticed quite a few of these errors in the event log :

Unknown SQL Exception -1 occurred. Additional error information from SQL Server is included below.
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 – Error Locating Server/Instance Specified)

Again this was not helpful, as I had other Web Applications on the same servers, which had no problem connecting at all!

Out of some desperation I decided to try detaching and reattaching the content database for the Web Application, and Voila!  The site came back online.   I do not have any idea why this was actually happening, however I’m putting it up here in case someone else comes across it.