Authentication / Proxy Issues

As of writing this page, there are a few authentication types, namely client certificates and NTLM that can't pass through Burp and need to be configured within Burp Suite itself. To configure authentication, go to settings and update the appropriate fields, the following is an example:

User options > Connections > Platform Authentication. You want NTLMv2; the destination host is the host in the URL of your application

References

Not able to log into certain websites while proxying through Burp - Burp Suite User Forum