So, someone recently commented on one of my addons (uploaded within the past few days, and brand new) to inform me that it was marked as "out-of-date" in-game. I assumed either it was an error on my part (typo or forgot to modify the file when I copied it from my template) or an error on their part.
However, the manifest appears correct
http://i.imgur.com/haAZ6PC.png
But the addon is marked out-of-date
http://i.imgur.com/RRq8Rnf.png
However, another addon which I wrote today has the exact same manifest
http://i.imgur.com/lvkHVX0.png
And is not marked as out-of-date
http://i.imgur.com/Ws13wmK.png
As an experiment, I copied the manifest file of the functional addon over the top of the existing one, changing the description and title, but it still is marked as out-of-date.
I can't see what I could possibly be doing wrong here. I'm obviously missing something, and hopefully it's something simple, but I just can't put my finger on what it is.