I am hosting the MP3 files from my archive in my Dropbox public folder and publishing them onto my WordPress site using the podpress plugin.
Of the three posts I have published this morning, two are fine. The player on the second post is muted. It will not play within the post, nor will it play when opened in a separate window or downloaded. When downloaded, the speaker icon on the right is greyed out, with a diagonal line through it.
The MP3 plays when I copy the Dropbox public link and paste it into a new browser window.