ADFS 2.0 401 Unauthorized Access

2017-12-01T11:25:44+00:00 October 28th, 2011|Azure|

We had an issue recently when setting up CRM 2011 IFD up. The issue was that internally we were unable to access the CRM website as it kept throwing a Windows Authentication box prompt up from our ADFS server. Then we eventually we got a 401.1 error after failing to authenticate 3 times.

We checked all IIS setting and ADFS configuration on the ADFS server and all of it was fine.

The issue turned out to be Loopback checking.

http://support.microsoft.com/kb/896861

  1. Click Start, click Run, type regedit, and then click OK.
  2. In Registry Editor, locate and then click the following registry key: HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlLsa
  3. Right-click Lsa, point to New, and then click DWORD Value.
  4. Type DisableLoopbackCheck, and then press ENTER.
  5. Right-click DisableLoopbackCheck, and then click Modify.
  6. In the Value data box, type 1, and then click OK.
  7. Quit Registry Editor, and then restart your computer.

As soon as we added this setting and rebooted server everything sprung into life and started working Smile