Just a litte info:
I found today a movie on the list of the fantasy filmfest (Germany) who have the exact same title and same release year, but the movie is totally different to this one, so I was happy to watch that on the big screen at the festival, but it's another one with the same name and the same release year.
I noticed, that this movie was released in Germany on April 23 (whooops) and they renamed it in Germany (and some less other countries) to "The Curse of Rosalie".
So... If you search now on IMDB for "The Harbinger", the result can be this movie:
https://www.imdb.com/title/tt13610158/?ref_=fn_al_tt_1 who is not the same as here in the topic.