Website Payments Pro - Merchant Country Issue for UK

I have just installed a new site with Zen Cart 1.5.1 and configured Paypal express which worked fine and payments pro which kept returning an invalid vendor error 26.
After a few days back and forth with Paypal Integration Support that have identified the problem.
I am in UK and set merchant country to UK

to quote paypal support

In the zen cart payment modules, PayPal Payments Pro installation you may need to select ‘USA’ as the Merchant Country. This is because zen cart has the wording for the requirements mixed up.
It states ;
USA and Canada merchants need PayPal API credentials and a PayPal Payments Pro account.
UK merchants need to supply PAYFLOW settings (and have a Payflow account)

When in fact UK merchants need PayPal API credentials and a PayPal Payments Pro account.

In the Express Checkout installation you should keep PayPal selected as PayPal mode and ignore Payflow-UK & Payflow-US

I changed the Merchant Country to USA and so far everything seems to work ok - although I need to do some more (international) testing.

Just thought this may be of help to anyone else suffering the same issue

Thanks for pointing it out. Evidently Paypal has changed something and didn't tell anybody. Again.

Hi legraphics, many many many thanks for your post.
I spent about 8 hours on the phone to PayPal and a number of more hours searching the net and found this post.
Paypal were hopeless, first of all I spoke to a bunch off muppets, who then passed me to the stage two muppets (email only, they don't speak to us mere customers) who sent me generic replies and then did not get back to me.
Posts like your where you have just found a solution and taken the time to share it are really appreciated by people like myself. Cheers!