After experiencing a bad glitch that frustrated the release of the windows rt 8.1 upgrade. The company has resolved the issue and now the update is now available for free on the windows store. The challenge with the boot configuration flaw as been resolved and those who want to update their device can do so now.
See official tweet by Microsoft below.
Windows RT 8.1 update available again for free in Windows Store. Go update your Windows RT and Surface RT devices now!
— Microsoft Support (@MicrosoftHelps) October 22, 2013