'Allo, deary! So ye say y'er being led to Adfly? Then don't worry, ye are on the right track. The download link will lead ye to Adfly no matter what, since this forum is up and running for free and ads are what keeps this site going.
At the top right hand corner of the Adfly page is a "Skip Ad" button. Ye will 'ave to wait five seconds before ye are allowed to click this button, but once ye do, it should lead ye back to the Feral Heart site/forum. Now, if m'memory served me correctly, it shall ask ye to log in again. This is just to confirm that ye do 'ave an account. Once done ye should be able to begin downloading the FH setup.
As for the page saying registration is closed, that is normal. Registration isn't always open, but since ye already 'ave an account {and 'ave hopefully already activated it} ye shouldn't 'ave to worry about that.
If anything I 'ave said seems foggy, just let me know and I shall do to the best of m'ability to get things working for ye.