Udeler generally works best with personal accounts. If you are using a Udemy Business or Enterprise account, Udeler may not be able to detect your courses.

If the video downloads but doesn't play, it might be corrupted or incomplete.

Since the original Udeler project is no longer actively maintained, it is highly recommended to use (a maintained fork) or the official legacy version if you can find a trusted source.

Download the .dmg file and drag the Udeler icon into your Applications folder.