I've found a way round the problem: The product(s) in your shopping cart is/are currently not available for order.
Remove the
My Shipping Address
details on aliexpress. This will give you a go for one order. However, you need to do it each freaking time.
However this works. It just doesn't do the trick for Germany. I can't just order to Germany somehow. Very strange. I don't know how this is possible. Anyone an idea?