Had a problem when opening the Knowledge Article from the Portal the other day. Down below is the output from the error.
The solution was to add the following register keys.
Disable the loopback setting on the Service Manager portal machine.
- Start Registry Editor (Regedt32.exe).
- Locate and click the following key in the registry: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanmanServer\Parameters
- On the Edit menu, click Add Value, and then add the following registry value: Value name: DisableStrictNameChecking Data type: DWORD (32-bit) Value. Radix: Decimal Value: 1
- In Registry Editor, locate and then click the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
- Right-click Lsa, point to New, and then click DWORD (32-bit) Value.
- Type DisableLoopbackCheck, and then press ENTER.
- Right-click DisableLoopbackCheck, and then click Modify.
- In the Value data box, type 1, and then click OK.
Found the answer here: Error when clicking on Knowledge articles in service manager 2012 portal
The error message in clear text.
The remote server returned an error: (401) Unauthorized.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Net.WebException: The remote server returned an error: (401) Unauthorized.