I was able to connect to a new repository that I owned on github but when I tried to connect to a much larger public repository, Torque3D, it gets to the importing phase but then fails after about 20 seconds with the following error
Message The credentials provided for the github source are invalid. (Source at github.) Table: Pull requests.
Time Mon Feb 26 2018 14:53:15 GMT-0500 (Eastern Standard Time)
Cluster URI https://wabi-us-north-central-redirect.analysis.windows.net