Enable NTLM authentication on non-Windows Firefox

On non-Windows Systems you may Encounter the authentication error „401 UNAUTHORIZED“ while trying to authenticate to SharePoint.

The support for the NT LAN Manager version 1 (NTLMv1) network authentication has been disabled in Firefox on non-Windows Systems since Firefox Version 30.0. NTLM is necesarry to be able to authenticate to SharePoint.

To enable NTLM in Firefox you have to…

1. Open Firefox
2. Access the config file („about:config“ in the URL line)
3. Change the following keys to true (double click on the key):
   1. network.auth.force-generic-ntlm
   2. network.auth.force-generic-ntlm-v1
   3. network.automatic-ntlm-auth.allow-non-fqdn
4. Restart your browser

After that you should be able to authenticate to SharePoint.