Event ID 14 – The start address cannot be crawled

I have just spent hours trying to get to the bottom of an issue with search in SharePoint 2010.  No results were being returned and the following error was reoccurring in the Application Event Log:

The start address http://wprintranet cannot be crawled.

Context: Application ‘Search_Service_Application’, Catalog ‘Portal_Content’

Details:

Access is denied. Verify that either the Default Content Access Account has access to this repository, or add a crawl rule to crawl this repository. If the repository being crawled is a SharePoint repository, verify that the account you are using has "Full Read" permissions on the SharePoint Web Application being crawled.   (0x80041205)

After spending hours checking the permissions, resetting passwords, removing and adding managed accounts, I was struggling to figure it out.  Each time I initiated a full crawl it would stop after 01:40 with the same error reported in the Application log.  As far as I could tell the permissions were all OK.

I eventually noticed Event ID 4625 (An account failed to log on) being logged in the Security event log each time the crawl ran.

Unfortunately, the error has nothing to do with permissions and is generated by the loopback check.  The fix for this was to add a new registry key:

1. Open Registry Editor

2. Navigate to HKLM\System\CurrentControlSet\Control\Lsa\MSV1_0

3. Create a new multi-string value named BackConnectionHostNames

4. Modify the new value and enter the hostname of the site that is hosted on the local server

5. Click OK and close Registry Editor.

More information on this issue be found here: http://blogs.technet.com/b/sharepoint_foxhole/archive/2010/06/21/disableloopbackcheck-lets-do-it-the-right-way.aspx