Thanks for the interest in this issue. I cannot post the URL publicly, but can send it privately if you wish to look into it.
I looked into the userprofiles and something is a bit off. Sometimes, when you click the userprofiles, it works, and then if you click again, it shows 404 error, but for most part, it is a 404 error message. Prior to 2.4.2, userprofiles was broken, but the 2.4.2 release note indicated the bug was fixed.
Also, when someone buys an article on OJS website, they are always required to have an account to do so (why can't people buy without registration?). But the issue is that when people register, they sometimes do not register correctly and so on their user account, it shows that they are not enrolled on any journal. As a result, the user becomes an orphan because the user is not enrolled in any journal. The user cannot receive any news about the journal if they are not enrolled. At first, I noticed that those who are not enrolled in a journal, but have bought and downloaded the article, when clicking their userprofiles via the payments records under subscription, it always generates an error.
Additionally, there are some issues with charaset, which I am trying to solve.