[Plugin: SoundCloud Shortcode] Widget Suddenly Not Working

I had the shortcode plugin working great up until this morning.

I tried to add a new shortcode to a post but all that showed up was a link: https://api.soundcloud.com/tracks/41963017, not the widget…

When I click the link it takes me to a page that says the following:
This XML file does not appear to have any style information associated with it. The document tree is shown below.
<error>401 – Unauthorized</error>

…
My site is DanielLlosa.com

HTML5

https://www.ads-software.com/extend/plugins/soundcloud-shortcode/