The g6_auth_nt.dll file is part of an unknown program developed by Gene6. It is not uncommon to find files that belonging to unknown programs yet still be able to identify the source. Many files are shared and thus identifying a single program is hard. However, the author in this case, Gene6, is easy to find.
Gene6 creates file transfer program (FTP) for the web, e-mail and blogs. These run in the background and most of the time you never see them. You might if you are a real techie and get heavily involved in that kind of stuff.
File Not Found
%programfiles%\gene6 ftp server\plugins
For the most part, the g6_auth_nt.dll error is a simple registry error. However, like most registry errors, this will cause the program not to work unless it is fixed. This means the blog, e-mail or web-hosting program will not work properly.
Since this program runs in the background and you do not have direct access, you will want to run a registry cleaner. ZookaWare PC Cleaner is the safest and most effective way to resolve this error. It is 100% effective and comes with a 60-day money back guarantee.