Invalid params error when playing podcast with Mopidy Mobile

I’ve been encountering an odd error when I try to play a podcast from the Pimusicbox. Specifically, it’s when I try to access podcast+https://feeds.publicradio.org/public_feeds/classical-kids-storytime/itunes/rss.rss#http://www.classicalmpr.org/story/2018/10/30/classical-kids-storytime-goldilocks-and-the-three-bears

When the error appears Mopidy Mobile prompts me to ignore or retry repeatedly. After a few cycles of ignoring or retrying (it doesn’t seem to matter which I choose) the podcast begins to play, but I’d love to know if there’s a way to avoid the error altogether.