Error with PayPal transaction

Hi! Using the free version to verify it works for our needs, but so far no luck. The code generated: This is some test text.[wpepsc name=”A test buy” price=”1″ align=”center”]

What happens: the button takes me correctly to PayPal, but when attempting to pay, via PayPal or anything else, it results in an error message:

Things don’t appear to be working at the moment. Please try again later.

As evident from the code before, we are not passing a currency, only a number. What’s wrong?

Thank you!