Demo has errors

Just noted, the demo store here has errors. All items I tried showed:

Products marked with *** are not available in the desired quantity or not in stock!

Hope it can be fixed.

That's just because it is a demo store, not a working store, so all items are set with a zero quantity in stock. That is the normal message that appears if someone tries to order something that is not in stock when "allow out of stock purchases" is set to no. Nothing to fix. No orders can actually be placed on the demo store.

I wonder, can't they have Paypal Sandbox account, or at least to be able to get up to a (then failing) payment process?