Cracking a niche program like MetaSynth—which is primarily built for macOS—is notoriously difficult. Sites claiming to offer a "full version" for free are frequently fronts for: Malware & Ransomware:
Here is a blog post exploring why users look for MetaSynth, the dangers of cracks, and better alternatives. metasynth crack
If you are looking for that specific MetaSynth sound without the risks of pirated software, consider these paths: Cracking a niche program like MetaSynth—which is primarily