The most generated errors being found on Opencart forum originates from contributed programming. The increased counters are caused by posted redundancies of the same solutions that were already provided prior.
It goes to the success page with the download page link but that sends people to their general account page and not the list of files they want to download. Be cool if the continue button on the success page goes to the file order page.
Strange thing is it worked until I had to do a re-install. Imported the db and orders are all good. I had to change the www preference in Plesk to allow admin panel to function properly.
"Speak softly but carry a big stick"