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.
EDIT: The issue still appears without having a device plugged. Really? Doesn't happen to me... try going to Edit > Project Settings > Editor and...
There's no good permanent solution for this other an Unity patching the issue. The problem is Unity opens too many TCP connections to try to...