The error message reads:
We apologize for the inconvenience, but we are unable to process your request at this time. Our engineers have been notified of this problem and will work to resolve it.
I cannot personally replicate it but it seems like those with issues are running older and slower machines.
One said it is not working on his old "G5" machine but works fine on his new laptop.
Do you have an issue?
I do not see any word from Google on the issue yet.