Sending HTTP response 401 - text/plain:401 UNAUTHORIZED.

Hanamichi Sakuragi 246 Reputation points
2020-09-01T11:58:16.31+00:00

Hi All,

I am getting Sending HTTP response 401 - text/plain:401 UNAUTHORIZED this error in ULS.

I can access all the sites on WFE.

Do you know where that issue coming from?

Thank you.

SharePoint Server Management
SharePoint Server Management
SharePoint Server: A family of Microsoft on-premises document management and storage systems.Management: The act or process of organizing, handling, directing or controlling something.
2,955 questions
0 comments
Accepted answer
  1. Echo Du_MSFT 17,176 Reputation points
    2020-09-02T08:52:28.337+00:00

    @Hanamichi Sakuragi

    According to my understanding, you faced the following situation:
    When you access SharePoint Sites through IE browser on the SharePoint Server, the system will prompt you to perform 3 times authentication, and then you will receive the "HTTP 401.1-Unauthorized: Login failed" error. But SharePoint Sites can be accessed normally on the WFE Server.

    This is because the "local loopback check" only permits NT Authentication to the localhost address for defined hostnames.

    Please run the following PowerShell in the SharePoint Management Shell to disable Loopback Check: 

    New-ItemProperty HKLM:\System\CurrentControlSet\Control\Lsa -Name “DisableLoopbackCheck” -value “1” -PropertyType dword

    You could refer to this article SharePoint 2013: Disable Loopback Check

    Thanks,
    Echo Du

    ----------

    If the response is helpful, please click "Accept Answer" and upvote it

0 additional answers

Sort by: Most helpful
Most helpful Newest Oldest

Your answer

Answers can be marked as Accepted Answers by the question author, which helps users to know the answer solved the author's problem.