I'm trying to integrate PayPal into my website using their PHP API. I've gone through the setup of creating a sandbox-merchant and sandbox-user account and I've put all the code necessary into the relevant pages and included my user/pass/key etc. in the functions page.
When I test however, I get as far as seeing the correct price, logging in, pressing "confirm payment" and then the little popup closes and I'm left at a "loading" page (URL https://www.sandbox.paypal.com/webapps/checkout/webflow/sparta/expresscheckoutvalidatedataflow?execution=e1s2) which never goes anywhere. Logging into my PayPal Sandbox account shows that the transaction was not successful.
Any ideas what's happening?
SOLVED
Turns out my server was disabling scripts in a coincidentally named directory with open_basedir (the bane of my existence on Plesk servers).
PHP's open_basedir was disabling php confirmation script. Coincidentally named directory.