I have the same problem! On Cute and Amazing it gives "ART" as an option to download, but it doesn't work. Although I can DL in Pes, it is a schlep. Maybe it is a temporary problem and we should ask Veronika to please help. We used to DL "art" before, without any problem.
This morning, I opted for 'save' instead of open, and it worked just fine. Maybe that's all it takes. I dislike v.6 because it won't let me save Grade C or D designs and many freebies are in that type.
I don't know for sure, but if you have a converter, you might want to try to convert it to the ART v6 and see if that will change it, if not I would go where you d/l and upload again. BTW Congrats on your first 100 flowers. Here is more for your bouquet!