When I go to mysite.com/marketplace/app/likes-plugin-204 and other store listings, it takes me to "mysite.com" 404 error page not found. This is not because of the upgrade. This has been going on for sometime.
Please check the forum section when posting. I moved this from SEUnite to SEPHP. I'm not sure of the issue though. Why are you going to your site to go to the store?
If you mean from the widget like here https://demo.socialengine.com/admin I'm not having any trouble there when clicking the listings.
But I do see they link to the marketplace old url so we'll update that too even though the redirect works fine for me, perhaps it doesn't work for you or some other people.