Successsful transaction ends with blank page

[plrz]

PrestaShop 1.4.8

PayPal module 3.0.9

 

The transaction succeeds, everything happens as it should in the back office, but ...

 

the last redirect back from PayPal, with a URL such as:

 

https://www.example.com/shop/modules/paypal/express_checkout/submit.php?token=EC-34162280772834336&PayerID=5GAYNGLNKJQAY

 

results in a blank page. Nothing. Zilch.

 

I can't see where or why something is going wrong.

 

I'll be eternally grateful for any enlightenment.

Edited September 9, 2012 by plrz (see edit history)