Graphic River Fonts will not install

I purchased two Graphic River Fonts, but when I try to install them on my Win 10 machine, they say the fonts are invalid.

I unzipped the folder and tried placing both the TTF and OTF files into my Fonts Folder from the Control Panel, but both said that the fonts were invalid and would not install.

What next?

Thank you,

Ask the author of the fonts for help

Thank you, @charlie4282. I will do that!