Corrigir Erro [RESOLVIDO]

Gostaria que alguém me ajudasse:
estou comeste problema
E: Malformed entry 55 in list file /etc/apt/sources.list (Component)
E: A lista de origens não pôde ser lida.
Configure as opções de repositórios para corrigir o problema.
E: _cache->open() failed, please report.a,

como resolvo

Mostre a saída do comando:
cat /etc/apt/sources.list

ealvarenga@ealvarenga-K43U:~$ cat /etc/apt/sources.list
# deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main restricted
deb-src http://archive.ubuntu.com/ubuntu xenial main restricted #Added by software-properties

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://br.archive.ubuntu.com/ubuntu/ xenial main restricted
deb-src http://br.archive.ubuntu.com/ubuntu/ xenial restricted multiverse main universe

## Major bug fix updates produced after the final release of the
## distribution.
deb http://br.archive.ubuntu.com/ubuntu/ xenial-updates main restricted
deb-src http://br.archive.ubuntu.com/ubuntu/ xenial-updates restricted multiverse main universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://br.archive.ubuntu.com/ubuntu/ xenial universe
# deb-src http://br.archive.ubuntu.com/ubuntu/ xenial universe
deb http://br.archive.ubuntu.com/ubuntu/ xenial-updates universe
# deb-src http://br.archive.ubuntu.com/ubuntu/ xenial-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://br.archive.ubuntu.com/ubuntu/ xenial multiverse
# deb-src http://br.archive.ubuntu.com/ubuntu/ xenial multiverse
deb http://br.archive.ubuntu.com/ubuntu/ xenial-updates multiverse
# deb-src http://br.archive.ubuntu.com/ubuntu/ xenial-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu xenial partner
deb-src http://archive.canonical.com/ubuntu xenial partner

deb http://security.ubuntu.com/ubuntu xenial-security main restricted
deb-src http://security.ubuntu.com/ubuntu xenial-security restricted multiverse main universe
deb http://security.ubuntu.com/ubuntu xenial-security universe
# deb-src http://security.ubuntu.com/ubuntu xenial-security universe
deb http://security.ubuntu.com/ubuntu xenial-security multiverse
# deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
deb http://br.archive.ubuntu.com/ubuntu/ xenial-backports multiverse restricted main universe
deb-src http://ppa.launchpad.net/tualatrix/ppa/ubuntu xenial Release
#deb http://ppa.launchpad.net/tualatrix/ppa/ubuntu/dists/xenial/main/source/Sources 404
deb-src http://ppa.launchpad.net/tualatrix/ppa/ubuntu/dists/xenial/main/source/Sources 404
ealvarenga@ealvarenga-K43U:~$

Remova as três ultimas linhas do arquivo:

deb-src http://ppa.launchpad.net/tualatrix/ppa/ubuntu xenial Release

#deb http://ppa.launchpad.net/tualatrix/ppa/ubuntu/dists/xenial/main/source/Sources 404

deb-src http://ppa.launchpad.net/tualatrix/ppa/ubuntu/dists/xenial/main/source/Sources 404 

$ sudo nano /etc/apt/sources.list
$ sudo apt-get update

RESOLVIDO!!!!
GRATIDÃO!

ME DEPAREI COM ESSE PROBLEMA NO UBUNTU 16.04.

E: Problem executing scripts APT::Update::Post-Invoke-Success 'if /usr/bin/test -w /var/cache/app-info -a -e /usr/bin/appstreamcli; then appstreamcli refresh > /dev/null; fi'

O MESMO FOI RESOLVIDO COM OS COMANDOS.

$ sudo dpkg --configure -a
$ sudo apt-get update
$ sudo apt-get dist-upgrade
$ sudo rm -vf /var/lib/apt/lists/*
$ sudo apt-get update
$ sudo apt-get dist-upgrade

OBS: OBEDEÇA ESSA ORDEM

E VIVA O LINUX.