Alright. A lot of people have been getting the "Couldn't Unpack natives" error including me. I saw on the MC bug tracker and it told me to move the Minecraft.exe to another folder. I moved it to my username folder (Owner) and made a shortcut on my desktop for it.
When I did this, I deleted the .minecraft folder and updated from scratch and everything worked fine. Try it out.
When I did this, I deleted the .minecraft folder and updated from scratch and everything worked fine. Try it out.