Hi Nikolai,
Right now, there is an issue in trying to directly buy Story Plus from the Story Landing Page. We are trying to resolve this on priority.
Meanwhile, please try out the following alternative steps to add Story Plus to your cart:
1. Navigate to adobe.com
2. From the top right, click Menu -> All Products
3. From the dropdown on products catalog page, select All software
4. Click “All Software” from the Dropdown
5. Scroll to 3rd page on the product catalog page
6. click on Join against Story CC Plus
7. Click on Add to cart.
Thanks
Aurobinda