I have this weird problem after I upgraded my PC and to Windows 10.
Of course I had to reinstall everything, including Hitfilm. I own the 4 Pro version I bought back in 2016.
I've tried to reinstall fonts I was using before on Windows 7, and none of them work -- not even the ones that I know for a fact previously did. TTF or OTF, doesn't matter.
I was previously using the Russo One font and it worked in HitFilm with Windows 7, despite being OTF format. I've now installed that font and roughly 10 other TTF fonts -- none of them show up in HitFilm but in other programs. I've tried restart, reinstalling, none of it works. And yes, it's directly installed and not a shortcut.
Before you recommend me TransType 4: I downloaded that but it was too new and the site was not secure. Not gonna install that.