Because version 12.4 is an older release, it is no longer hosted on the main FL Studio download page . You must access it via the Image-Line Forum Legacy Installers Archive : Image-Line maintains a specific forum thread for Historical Installers Account Requirement
In an era where FL Studio has moved on to versions 20 and 21 (and beyond), why does the search term "FL Studio 12.4 download" remain popular? Fl Studio 12.4 Download