http://hkmdb.com/db/movies/view.mhtml?id=8328&display_set=eng

What does HKMDB lists as the year of the movie? Year of production or first release?

And, where did you find the year of Martial arts master Wong Fei Hung?

We use the year of first release in Asia. According to the HKFA "Year of Troublesome Night 3" was first screened in 22. 01. 1999

MAMWFH with CKL as WFH, HKFA says 04. 12. 1992

No problem with TN3 then
But about MAMWFH I have strong suspicion that the movie was shot at least in 1990. But did MAMWFH had theatrical run? I have a HKFA's catalog of movies released in cinemas and there is no even such a movie.

HKFA entry citing 4.12.1992:
HKFA - Martial art master Wong Fai-hung