Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
WWDC 2013 Tickets Sell Out In Less Than 120 Seconds
Yesterday Apple announced WWDC 2013 with tickets going on sale at 10 a.m. PDT / 6 p.m. GMT and already the tickets for the conference have sold out in less than 2 minutes. WWDC 2012 took 2 hours for Apple to totally sell out of tickets so it is an expected improvement to say the least.
If you couldn’t get tickets this year don’t worry, because you’ve probably saved yourself a lot of money, as the tickets for WWDC cost $1,599 USD this year. You can watch the full event here www.MacReviews.com/WWDC where we bring you live coverage of the event its self.