While adding a new Data Source to a Sharepoint Site for SQL Reporting Services, I kept getting the following error:
An unexpected error occurred while connecting to the report server. Verify that the report server is available and configured for SharePoint integrated mode.
Ummm…. OK. It is configured for SharePoint integrated mode. Quick Google search reveals the following MSDN site: Reporting Services SharePoint Integration Troubleshooting
While perusing the troubleshooting page, I ran across root cause number one (which actually refers to browsing central admin from the machine on which central admin is installed):
The usual root cause for this error is loopback checking. Loopback checking causes credentials to fail to be passed on POSTs back to the server. This issue occurs only if a host header or DNS name is being used for the SharePoint site.
Since the problem I had was creating a Data Source between the SharePoint site and the report server, while connecting to the SharePoint site from a “client”, I figured this didn’t really apply. However, since Sharepoint sometimes gives more detailed errors when connecting to a site from the machine on which the site is hosted, I figured I’d logon to the site from the server and try again. Unfortunately, I got the classic LoopbackCheck error (accessing an IIS site from the server on which the site is hosted results in continuous prompts for credentials).
After a quickly adding the disableloopbackcheck key to the registry, something I describe in too much detail here (and after double checking the key because I accidentally included a leading space in the DWORD value and still couldn’t connect), I was able to access the local SharePoint site, and found to my utter amazement, I was able to create the Data Source. Not only while connecting from the server but also from my client. Damn LoopBack Check. I know its a security feature, but it continuously gets in the way of actually running an operational IIS server.
Paul Beckford is an IT professional based in Denver, Colorado. Over the last dozen years, Paul has worked “hands-on” in an IT Operations role deploying and supporting a multitude of technologies, such as Network Infrastructure, Windows and Linux servers, most Microsoft Back Office & Infrastructure applications, Virtual Computing, Mobile Computing and Information Security.