Quote Originally Posted by marton_1 View Post
Strange thing is nobody has used Paypal so far today on my site so what is triggering paypalwpp.php?
Perhaps they "started" checkout but didn't complete ... hence no evidence of completing purchases yet.
Quote Originally Posted by marton_1 View Post
I have this error;
3-Dec-2015 13:04:29 Europe/Zurich] PHP Warning: Illegal string offset 'id' in ....../catalog/includes/modules/payment/paypalwpp.php on line 200.

...

I am using v1.5.1 with the classic template

Anybody have an idea could be causing this?
Yes. ZC v1.5.1 is not compatible with PHP 5.4, and one of the symptoms of that is about 50 things that can trigger "Illegal string offset" errors.
Ref: https://www.zen-cart.com/content.php...o-run-zen-cart

You need to upgrade.