Had this problem with an earlier update, spent more than 1 hour with Apple with some screen sharing, only option offered in the end was reset my macbook and see if it works (and it worked), else they would have transmited problem to their engineers.
FYI, the weird thing we found out while on the phone was that in Disk Utility, it showed my disk nearly full whereas it wasn't at all (and "get info" on the disk showed the proper available size)
So even after a clean install it's not available. I'm downloading the update from Apple now to try again. It did want to install beta 5, but after turning off beta updates I says no updates available again.
Still won't install the download right from Apple:
That's a beta of 10.10 (the release build was 14A389.) I'm surprised it hasn't expired. Download the full 10.10.3 installer from the App Store and install from that.
Hmm, that's strange. I just did an Internet restore last night. I turned off beta updates in preferences. Does that change it on Apples end, could I just do another Internet restore?
Or should I just dl the file? I'd rather to a clean install than an upgrade if possible.
Thanks for the help.
If nothing else, you could download the 10.10.3 installer and make a USB installer from that. Internet recovery should have put a version of 10.9 on the computer so I suspect you just did a recovery install. Personally I wouldn't worry about a clean install.
Download the full installer from the App Store/Purchases tab.
If you don't see it in your Purchases, then link through from Apple's Yosemite product page.
http://www.apple.com/osx/
Click the "Update Now" link, and that will take you to the right place to download Yosemite.