Affects Version/s: 2.0.1004 (Mac OS)
Fix Version/s: 2.1.2480-2.1.2482
Mac OS X 10.12.6
Fresh install of Launcher using dmg from minecraft.net.
Launcher requires connection to youtube.com.
youtube.com access is blocked in the network, at the firewall.
When youtube.com is not allowed, Launcher opens a blank window and freezes/pauses/halts indefinitely.
DNS query for youtube.com is observed when no other applications running. The Clue (tm).
Problem is resolved when youtube.com is allowed. Problem is reproduced when access to youtube.com is again restricted.
Also, version number and copyright date in Lauchers' about says 1367 (c) 2015.
The version is not visible unless the launcher actually starts. Maybe you should sync those up.