Well, I don't know how to resolve that issue, and, I think you know, Wp-Pro-Quiz has not been updated in 5 years, though it miraculously continues to run without a hitch. (Hats off to the plugin author,!) So I can't contact him, but I can and have contacted you. 😉
What it means for me, I'm afraid, is that I won't be able to use the wpDiscuz User & Comment Mentioning add-on. 🙁 ... which is a pity, as, as a new customer, I am quite happy with my purchase of your bundle.