There are several reasons why users may want to download YouTube Downloader 2.1.6:

If it fails, try using youtube.com/watch?v=XXXXX (not the shortened youtu.be link) and disable HTTPS if the app has such an option (though this is highly insecure).

Using "old version" software from unofficial third-party sites is highly discouraged for several reasons: Malware Bundling

: Many third-party downloaders are flagged by antivirus software as Potentially Unwanted Programs (PUPs) due to bundled adware.

If you are looking for an Android APK, version 2.1.6 can sometimes be found on the Internet Archive Media Downloader (v2.1.1):