Unfortunately this problem still persists in 10.11.2 and also with Beats Wireless just bought the last days (not the newest firmware on them, though). Had this problem, too. Sorry, for my bad English, by the way, but I was extremely angry about that and found this thread on google, just wanted to help others facing this.
I'm from Germany and a software developer myself. If I or any other person of the companies I work for would bring out such a bugged, obviously untested mess of a software (there seem to be a lot of others affected by this), I or he would be fired the next day without any question! I will probably stay by my B&Os and send this headphones back, as I would be ashamed of wearing this brand in public transport.
My environment: OSX 10.11.2 El Capitan, Macbook Pro late 2015, Safari 9.0.2 and Chrome 47. Also tried it on my business HP with Win 7, as someone mentioned it here, but was the same with it.
What I did: Just the things in the description, installed the Beats Software (by the way, Webinterface with Sockets for a firmware update, are you kidding me?), plugged the headphones in with the original Beats USB Cable. Software recognized them, started Update, boom! Update interrupted without doing anything. After that, the white LED bulb circle of death going on and off. Even after turning the headphones off, they went on again and stayed in update mode, even after reset, whatever. Unplugged, plugged in again, switching them off and on again, refreshing the update website, rebooting the machine, nothing.
If you are facing this, try this to complete the update: Unplug the headphones, refresh the update website, that there is the animated waiting circle, searching for Beats. Turn the Beats off (by holding the power button for about 4-5 secs), plug the Beats in, at the same time, turn the Beats on again, BUT keep holding the power button! If I released it (as seen in the description for resetting it), it was the same thing again: Can't find the beats, "Are you completely dumb and plugged them in?"-site coming up, button to "Contact our genius somewhat and spend your valuable time, cause we can't apply software"-website...
So just KEEP holding the power button. Then, the update unexpectedly went on with step 2 after waiting a few secs. But as I wrote before NEVER stop holding the power button of the headphones during that update, until it is finished!
Hope, this helps some people out there. And Apple/Beats: Be ashamed for that really poor QA. Wasn't the first time. WLAN not working correctly for nearly 3 months after 10.10... was there something?!
Regards