Feed not validating

Using the newest version of the plugin, the RSS feed would not validate.

I narrowed down the issue to be the substr you are doing on the itunes:subtitle cannot exceed 255 characters, but you are substr’ing it to be less than 3950. Therefore, your feed doesn’t validate with other services like Feedburner, and Blubrry.

I was able to use my own feed-podcast in my theme, but you should probably update your default file to cut off at 255.

https://www.ads-software.com/plugins/seriously-simple-podcasting/