This error usually occurs due to the wrong path to the downloads folder after AVD add-on and browser update or reinstallation.

As one solution please try to change the path for Downloads to another folder or reset it to default at the AVD setting page in Downloads section.

You should also try to uninstall Ant Video Downloader (Native messaging host) from Windows Settings - Apps & features menu and install the latest version using installer from here: https://www.ant.com/video-downloader/native/windows/latest

If you still encounter any issues after those operations, please contact our support.