Downloader was working fine on first 4 downloads of you tube videos on the next one it gave me an errore message that said "this link needs to be opened with an application" and "sent to: ummy". I am using windows 10 and firefox browser.

Here is a capture of the screen. 

Do you have Ummy Video Downloader installed?

Which button do you click on and in what quality do you want to download?

Send a screenshot and indicate which button you click.

Got it resolved. Did not realize that the "down arrow" provided download options.  Working fine. Thanks.

Ок.