Hello, usually method 4 in the user manual works.
(It's on page 15 in the manual, a more detailed step-by-step instruction is on page 16)
Basically, you need to open up terminal and type sudo chmod +x (fpvfreerider.app)
It should look something like:
chmod +x /Applications/FPVFreerider_Recharged.app/Contents/MacOS/FPVFreerider_Recharged
or
chmod +x /Applications/FPVFreerider.app/Contents/MacOS/FPVFreerider
(adding sudo at the start, if needed)
Hope that helps!