I tried the new map for a second time, but the results where the same.
All that appeared was a blank page, and no possibility to go back to the old map.
Running on Safari Version 9.1.3 (9537.86.7.8) on MacOS X 10.9.5
So I keep using the old map.
P.S. By using Firefox I was able to view the new map and found a link to return to the old map.
Switching between old map and new map should always be available!