Unfortunately, it is no longer possible to display new Picasa Web Albums/Google Photo Albums using the Picasa Web API (although the API can still be used to display Picasa Web Albums created prior to Google's acquisition of Picasa, which is why the option remains in the WP-Juicebox interface).
I am not aware of any workaround for this. (There would need to be an API which can fetch the images from the servers and the API just works for older albums.)
If you want to create new galleries in your WordPress site, I'd recommend using a different image source (the WordPress Media Library, Flickr or a NextGEN Gallery).
I realise that this does not directly solve your problem but using a different image source might be the way forward. Uploading your images to your own WordPress Media Library would mean that you have total control over your images and are no longer at the mercy of a third-party image host who can change their policies (and consequently access to your images) whenever they like.