Perfect Storm Mod webpage: Certificate error?

As I upload new videos of me playing Project Wingman without buying anything on my first playthrough, I went back to go on a check of Perfect Storm Mod that recently wasn't yet checked of (whether it's releasing new updates or not). Apparently, unlike before, I got myself an issue opening this website, which the domain has changed to host new website. Seems like the website has issues with certificate, which makes it being flagged as malicious for phishing or any sort. Apparently, I have safety measures when doing this. Flagfox addon is used to check if this website exists, and it did. Windows Sandbox or a virtual machine will be a perfect solution to access this suspective website, and apparently there was no issue going on with it. It loads normal webpage with nothing to worry about. So, my question to you is, does any website that is safe has issues like this? For an unofficial modding website, this is uncommon, because many websites don't have issues with certificat...