PayPal sandbox problem

[tsrplatelayer]

I am having trouble setting up PayPal express - I am testing with sandbox and have logging enabled. The logs can be downloaded at http://www.freight-stop-shop.co.uk/paypal_log.zip

I would appreciate it if someone could take a look and offer advice.

Is it something I have/haven't done - or is it a case of raising a ticket at PayPal.

Thanks in advance.

[tsrplatelayer]

I was able to establish communication with PayPal by going to the business account, removing the API credentials and then requesting new ones. These were then entered into my cart - and test with sandbox worked.