A Unity ID allows you to buy and/or subscribe to Unity products and services, shop in the Asset Store and participate in the Unity community.
Separate names with a comma.
I am facing the same problem and unable to resolve since 3 days, i have used Unity 5.6.1f1, Unity 5.6.2f1, Unity 2017.1.0f3 and Unity 2017.1.0p3...