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
Apple Release WWDC 2012 Schedule With Keynote For June 11th 10am PST
Apple today announced the time and date for the most anticipated event happening at WWDC 2012 , The Keynote. Apple today released the full schedule for the keynote which stated the keynote will take place at 10 a.m PST on Monday 11th June. If you are lucky enough to be attending WWDC 2012 then Apple also released an app for you which can be downloaded here.
If you are not going to WWDC 2012 but what to be kept up to date make sure you check out our coverage here
WWDC 2012 Live