The Darts game has been completely removed from FlyOrDie.  It’s no longer advertised on the main site, nor are there any active system tournaments or official links to it - 

https://www.flyordie.com/

If a game is not listed or advertised on the site, it means it is no longer supported by FlyOrDie.  While it might still be possible to access older versions through outdated links or cached files, please note that these are unsupported and may not be secure.

Unfortunately, that means any issues or errors with the old Darts game are outside FlyOrDie’s current platform and cannot be fixed.