Do you know if you are running the BuildMaster web application through the integrated web server, or if it's hosted by IIS? For the integrated web server, ensure that its service runs under Administrator as well. If you're using IIS, you'll have to verify that the app pool's identity is running as the Administrator account in addition to the BuildMaster service. Right now we are in the process of writing a knowledge base article that will give step-by-step instructions with regards to connecting to GitHub since that seems to be the most common hosted solution for our Git integration.