That’s strange… Maybe you have not downloaded every file?
Please follow this steps:
1. Go here and click on Code green button and then “Download ZIP”.
2. Go to download folder and unzip it
3. Open KiCad
4. On KiCad click on File > Open Project
5. Navigate to the unziped folder Thor/electronics/ControlPCB and open the ControlPCB.pro file.
It should properly open the KiCad project, if you still get this error let me know and I will look for another way to send you the kicad project 😉