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401 Unauthorized Access Error - Firefox 30 for OSX and SharePoint (IIS Authentication failure)

This article explains a workaround for Firefox version 30 on a Mac when users are not prompted for authentication to certain websites, but rather receive a 401 unauthorized access error.

Apple computers (OSX) running Firefox 30 cannot connect to SharePoint sites ( or IIS-backed intranet applications. Firefox (30.0) for Mac displays an error message "401 UNAUTHORIZED" when trying to go to any SharePoint site - the authentication prompt is never displayed.


  1. Launch FireFox.
  2. Type about:config into the address box, then click the button saying I'll be careful, I promise.

  3. In the search box type ntlm, the screen auto-filters to some properties.

  4. Locate the line "network.negotiate-auth.allow-insecure-ntlm-v1", then double-click it to change the value from false to true.

  5. Open a new browser tab within FireFox, then browse to the site. You should now be prompted for credentials.

Keywords:FF   Doc ID:41933
Owner:Joe M.Group:University of Chicago
Created:2014-07-17 09:50 CSTUpdated:2014-07-18 13:07 CST
Sites:University of Chicago, University of Chicago - Sandbox
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