Mono for Android v1.2.0.24718.zip refers to a specific legacy version of Mono for Android (now known as Xamarin.Android
Mono for Android Version 1.2.0 (Build 24718)
Official distributions of Mono for Android v1.2.0.24718.zip are no longer available from Xamarin or Microsoft. However, if you have a valid commercial license from the era, you may retain a copy. For historical research: Mono for Android v1.2.0.24718.zip
Additional Resources
Expanded API Coverage: Version 1.2 focused heavily on supporting more of the Android Gingerbread (2.3) and early Honeycomb (3.0) APIs. Mono for Android v1
Mono for Android v1.2.0.24718.zip: A Game-Changing Development Tool for Android App Developers
Android API Levels: Older versions of Mono cannot target modern Google Play Store requirements (API 34+). Mono for Android v1.2.0.24718.zip
The pain buried in the file