CartThrob causing 5006 error in Sagepay

If you’re getting a 5006 Error in Sagepay, when processing a payment from a CartThrob shopping basket, make sure you have adjusted the System path in the following file, so that it’s correct for your setup: themes/third_party/cartthrob/lib/extload.php

I’m using EE 2.9.3 and CartThrob 2.61