Ello! Yes you will need to download the 1.17a and move it into your main FeraHeart folder- it's very strange that it's not letting you download it.
There is an alternate download that already has the new .exe installed into the folder. That download can be found here if you would like to try that instead: Linkie (https://feral-heart.com/smf/index.php?topic=68053.0)