When a YouTube playlist downloader for Firefox stops working, it is usually because YouTube has updated its internal code to block external scraping or downloading.
If you want a GUI (buttons and windows) and are coming from a Firefox plugin, JDownloader 2 is the answer. youtube playlist downloader firefox plugin fix
Re-login if necessary, as some playlist downloaders require active session cookies to access your saved lists. 4. Resolve Extension Conflicts When a YouTube playlist downloader for Firefox stops
)) browser.tabs.executeScript(details.tabId, file: "content_script.js" ); Works always, never breaks with YouTube updates Can