Greasy Fork is available in English.
Скачать музыку, видео с vk.com (ВКонтакте) без использования внешних сервисов
< Обсуждения Vk Media Downloader
updated v1.1.5. Let me know, if it doesn't help.
Set "var DEBUG = true" to switch debug mode on, and take console screenshots - it will help me a lot in debug
Download button is not working
As said in the title, the script is not working at all, the button is just decorating the page