This just happened to me on 1.8.7 with a brand new download of the launcher, v1.6.11. I had been playing with it opened to LAN and one other person (who had logged off before I exited). I had to kill the window forcefully.
latest.log file attached. This has been happening to me ever since I can remember on 1.8+
OS: Windows 7 x64 SP1 Professional
Proc: Intel Core i7 940
Motherboard: EVGA x58 SLI
VGA: MSI AMD 6950
RAM: 12GB
Java: 8 Update 31 (64-bit)
@TheRSC it certainly seems like it's been overlooked. I reported it back in 1.8 and at each update when it still happened came back to re-report, but other people kept beating me to it. Been following it the whole time and the only updates I ever see are more reports of it. No one ever comments on fixing it... 😞