Paypal order doesn’t process

I tried to place a test order using PayPal as a payment method. Upon placing the order I get redirected to a page called Checkout that has nothing on it except for that headline. I’ve set up the plugin so it should be redirectingto PayPal but it doesn’t. I changed the PayPal settings to displaying a link instead – still nothing.

The order gets listed as “pending” in the back-end. It doesn’t seem to get processed at all because when I add another product to the shopping cart, the first order still shows as unfinished.

It’s only PayPal. Bank transfer works nicely.

I’ve just updated TheCartPress to the lates version but I don’t know if that’s the rreason. All I know is that last I checked (a year ago admittedly), it worked.

Any pointers are welcome.
Thanks, Max