Hey there, I also face this problem regularly with every other FVNs except for some. Since the file is unlikely to contain any harmful file/virus, I just disabled the virus detection system while downloading and every time before opening up the game.
I haven't tried downloading it yet; did you already and not have any issues? I assumed it's a virus purely because this game is ancient and hasn't been updated in years, nor has the dev's X page, and the webpage is dead. So I figured scammers felt safe to upload a fake version.
EDIT: Though, apparently the Patreon page was just updated and this is an official release?
EDIT 2: Ah! I checked the user, since if it were a scammer they probably would have registered recently. Registered in 2018 and has plenty of posts and followers, so it should be safe.
Sorry for late response. I have this problem with most of my FVNs. Northern Lights, Raincheck, After Class, The Smoke Room, etc. I don't have any issues with my laptop. The antivirus will keep notifying me that these FVNs' files are threats to my laptop though, but other than that everything is working fine. The FVNs I downloaded come straight from the publisher, so there should be no malicious files, but I still face this problem. And if I forget to disable the anti-virus and play the game, the system will register the file as corrupted and don't allow me to open the game anymore, thus I have to re-download the entire thing.