apt-get update error after dpkg --add-architecture i386

I have recently put Chrubuntu on my HP chromebook 11 (it's ARM). I currently have Xubuntu-desktop lts, checking version gives Ubuntu 14.04. I'm following this tutorial: install kingsoft office ubuntu 14.04

After:

sudo dpkg --add-architecture i386

I wrote:

sudo apt-get update

but always get this:

Err http://ports.ubuntu.com trusty-security/multiverse i386 Packages   404  Not Found [IP: 91.189.88.140 80] W: Failed to fetch htt=p://ppa.launchpad.net/iaz/battery-status/ubuntu/dists/trusty/main/binary-armhf/Packages 404  Not Found    
W: Failed to fetch http://ppa.launchpad.net/iaz/battery-status/ubuntu/dists/trusty/main/binary-i386/Packages 404  Not Found    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty/main/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty/restricted/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty/universe/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty/multiverse/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty-updates/main/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty-updates/restricted/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty-updates/universe/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty-updates/multiverse/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty-security/main/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty-security/restricted/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty-security/universe/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
W: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/trusty-security/multiverse/binary-i386/Packages 404  Not Found [IP: 91.189.88.140 80]    
E: Some index files failed to download. They have been ignored, or old ones used instead.

I've tried to update the sources.list but that didn't help, it replaced ports.ubuntu with us.archive.ubuntu but same errors.

Solution 1:

It was not even supposed to work. ports.ubuntu.com does not contain i386 packages. You have to manually edit /etc/apt/sources.conf and add proper package mirror there.