It might be my ISP. I can access all functionality of OPU on my sister's internet, who has a different ISP than I do. And I tried several different browsers, and all of them had the same issues, so the only link that is the same for all, is the ISP or the router.
However, as I'm typing this, the emoticons have come back, so maybe the issue is resolved. Yep, only OPU is the issue.
EDIT: I can visit the homepage again. So it may be fixed. I dunno, as I don't think anything on my end fixed it.
If the issue returns, I'll post again.