Originally Posted by SolApathy
Here is some information regarding the update (1.26.502.12) for AT&T models.
From the site:
Small update that fixes a few things in regards to the Media Link HD, which AT&T gave out to those who preordered HTC's latest and greatest. Specifically, some folks hadn't been able to connect to HTC's high-def streamer because of a software glitch. That glitch has been fixed and is now ready to download. It's a small, 269KB update, takes just a minute or so to do, and basically makes your life seem a little brighter. And fixes the Media Link HD connection.
AT&T HTC One gets fix for Media Link HD connectivity | Android Central
this is not the update. The media link update was released like 2 weeks ago. The one that got released today is different.