I just started getting this error today when I wanted to re-update Minecraft. I then tried deleting the folder entirely and re-downloading, same issue. I then looked up this issue and the most common fix is disabling your firewall/anti-virus, I have McAfee and since there wasn't a clear option to turn off the Anti-Virus (could turn off firewall AND add Minecraft as an exception which I did both) so I closed out of it and I got the same error, I then restarted my computer and same problem. Anyone know how to fix this?
The Anti-Virus/Firewall I use is McAfee SecurityCenter