Apple Print products Germany store not working

I am using Photos Version 1.0 (209.52.0). When I click on the button BUY BOOK I get the following message: "The store is currently down for updates. We'll be back shortly." It doesn't matter what country I select in Photo preferences. The option "Print product store account..." is greyed out. I have checked my account. All the payment and address information is uptodate.

Any ideas what might be wrong?

Thanks, Bernhard