Ummy Video Downloader has stopped working

Starting today, Ummy Video Downloader has stopped working. Tried uninstalling and reinstalling it to no avail. It seems to be unable to resolve YouTube links to get qualities (it shows the thumbnail though). On retrying, it sometimes shows one quality at random (sometimes 144p, 360p and 1080p). Downloading it does no good - the download goes to 100% but the file is nowhere to be found in the selected download directory.