Error message when clicking Paypal button

[mandapanda]

Hi there,

I'm new to Presta shop and trying to create and configure my shop. I've added the Paypal module and i had the message that I'm now able to accept Paypal payments. I then posed as a customer to see if it worked and as soon as I clicked the paypal button in my shop i received this error messge.

 

 

Error occurred:

Please try to contact the merchant:

1. <b>PayPal response:</b>
2. ->

 

Please can anyone help? I'm desperate to get the basics of my shop set up before i spend hours listing producs. Thanks in advance