Today, adsense control panel https://www.google.com/adsense/ is not opening on IE at my end. Do u able to open at ur end?
I read in a post somewhere (but don't take this as fact) that Adsense went down for a short while yesterday, about the same time as you posted. If I'm wrong I apologise.
I would suggest that you do a total shut down of your pc. Wait 3 minutes and try again. This has happened to me before and I went nuts trying to figure out why. So, now when anything wierd like this happens, I DON'T go for the shutdown restart - I just do the total Shut Down, Wait 3 Minutes and Re-start. This has always worked me, except in the few cases when the google site was actually down for upgrades, maintenance, etc... This happens at least one or twice a week - mostly on saturday or sunday nights.