Please upgrade to 2.2 here.
The 2.0 and 2.1 branches are no longer being updated.
I installed Play MP3 Links add-on, and enabled it. I made a post and inserted a link that refers to an mp3 file (from URL link stored at Fileden). But I don't see the player button. I am new to Vanilla and could have screwed something up. Any ideas what I did wrong ? Thanks for any help.