As expected, Google has finally and officially retired the old Google AdSense interface for the new one that rolled out two years ago.
Now when you login to the Google AdSense console, you will be taken to the new interface without a link to "return to the old interace."
There are many many complaints about this in the WebmasterWorld forums.
Personally, I switched over to the new interface years ago. But many did not and now have no choice. One publisher said:
Google needs to put a giant banner over the employee entrance -"Just because you CAN do something, does NOT mean that you should."
Rather than -
"Let's try everything - something might work."
Another publisher said, "That ruined my afternoon!"
Anyway, we had two years and Google was very transparent about the switch over.
Forum discussion at WebmasterWorld.