This developer is not correctly informing you that you cannot download high definition, 1920x1080 or greater, videos from YouTube or other streaming video sites without needing to pay the developer for this service. If this were true then, you would not be able to use an open source project like, youtube-dl, to download these high definition video streams, which you can still do as of today. Also, there are many other download managers, such as JDownloader, which can scan the URL and download these high definition videos. So, this is a devious tactic by this developer for financial gain only, as opposed, to being upfront and honest about wanting more donations. They are making up an excuse and blaming YouTube or other sites that offer high definition streams. Try for yourself, using youtube-dl, VLC, JDownloader, IDM, etc. and you will see that you can download these high definition streams.