Firefox recently disabled pre-NTLMv2 authentication in Firefox 30. This can cause issues in SharePoint and other IIS based sites. To re-enable NTLMv1 support type about:config in the location bar, click the “I’ll be careful” button, find network.negotiate-auth.allow-insecure-ntlm-v1, double-click on it to change the value to true. Below is what Firefox wrote in their release notes. NTLMv1 auth has…