Quote Originally Posted by simon1066 View Post
You haven't listed the other mods you have installed, but if you are using OPC then I suspect you need to edit the jscript_square.php in pages/checkout_one
I have OPC installed and jscript_square.php is already in the directory 'checkout_one' where it should be. However, it is currently disabled because I have a different issue with it and am in contact with Cindy who developed it about that issue.

jscript_square.php is also in 'checkout_payment'