Access denied to install directory

[Fitch]

Hi all.

I use Linux Ubuntu.
I had Makerbot running on Ubuntu 14.04 32 bit, then did a clean install to 16.04 AMD64.

I have followed the instructions on:
http://support.makerbot.com/learn/ma...or-linux_11262

and everything went well, up to the point:

sudo apt-get update

at which point the terminal complains:

E: Failed to fetch http://downloads.makerbot.com/makerware/ubuntu/dists/xenial/main/binary-amd64/Packages  403  Forbidden [IP: 54.240.166.62 80]
E: Failed to fetch http://downloads.makerbot.com/makerware/ubuntu/dists/xenial/main/binary-i386/Packages  403  Forbidden [IP: 54.240.166.62 80]

So what's wrong?
I've attempted to get a new key, and as previously, there were no errors.
I now have a 3D printer with no software to run it.

[Fitch]

Anyone out there?