Erro ao abrir o centro de software do Ubuntu [duplicado]

Question

Sou novato no Ubuntu e tenho esse problema em que não consigo abrir o centro de software. Na parte superior direita da minha tela, há um ponto vermelho com uma linha branca horizontal. Enquanto clica nele diz abaixo;

Error opening the cache
E:Malformed line 56 in source list/etc/apt/sources.list(dist parse),
E: the list of sources could not be read

O que devo fazer para superar esse problema?

Atualização: tentei a atualização e o que recebi foi:

E: Malformed line 56 in source list /etc/apt/sources.list (dist parse)
E: The list of sources could not be read.

Atualização 2: quando eu digitei cat /etc/apt/sources.list , Tudo que eu voltei foi:

UPDATE 3: Eu fiz o que você disse e é isso que aconteceu

~$ sudo rm -vfr /var/lib/apt/lists && sudo apt-get update
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_universe_source_Sources’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_restricted_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_universe_i18n_Translation-en’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_multiverse_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_main_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_Release’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_restricted_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_main_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_multiverse_source_Sources’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_Release.gpg’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_universe_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_restricted_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_main_i18n_Translation-en’
removed ‘/var/lib/apt/lists/extras.ubuntu.com_ubuntu_dists_raring_main_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_restricted_i18n_Translation-en’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_main_i18n_Translation-en’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_restricted_binary-i386_Packages’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_universe_i18n_Translation-en’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_Release’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_Release.gpg’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_multiverse_binary-i386_Packages’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_Release’
removed ‘/var/lib/apt/lists/extras.ubuntu.com_ubuntu_dists_raring_Release’
removed ‘/var/lib/apt/lists/extras.ubuntu.com_ubuntu_dists_raring_Release.gpg’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_restricted_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_universe_i18n_Translation-en’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_restricted_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_restricted_i18n_Translation-en’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_main_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_multiverse_source_Sources’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_restricted_i18n_Translation-en’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_main_i18n_Translation-en’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_multiverse_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_universe_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_restricted_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_universe_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_main_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_main_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_restricted_source_Sources’
removed ‘/var/lib/apt/lists/lock’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_main_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_universe_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_main_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_multiverse_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_universe_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_multiverse_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_multiverse_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_restricted_i18n_Translation-en’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_universe_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_restricted_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_universe_i18n_Translation-en’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_multiverse_i18n_Translation-en’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_multiverse_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_Release.gpg’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_main_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_Release’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_universe_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_main_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_universe_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_Release.gpg’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_multiverse_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_main_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_restricted_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_main_i18n_Translation-en’
removed ‘/var/lib/apt/lists/extras.ubuntu.com_ubuntu_dists_raring_main_binary-i386_Packages’
removed directory: ‘/var/lib/apt/lists/partial’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_multiverse_i18n_Translation-en’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_restricted_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_restricted_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_universe_source_Sources’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_universe_binary-i386_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-updates_multiverse_i18n_Translation-en’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_main_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring_multiverse_i18n_Translation-en’
removed ‘/var/lib/apt/lists/extras.ubuntu.com_ubuntu_dists_raring_main_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_main_binary-amd64_Packages’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_multiverse_source_Sources’
removed ‘/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_raring-security_universe_source_Sources’
removed ‘/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_raring-backports_multiverse_binary-i386_Packages’
removed directory: ‘/var/lib/apt/lists’
E: Malformed line 56 in source list /etc/apt/sources.list (dist parse)
E: The list of sources could not be read.

    

Answer 1

Eu também não sei muito sobre o Ubuntu, mas o que parece estar acontecendo é que sua lista de fontes de software está corrompida (a lista é o arquivo que contém todas as fontes do software, portanto, se você atualizar o software, sabe onde procurar). Eu tentaria abrir o terminal e digitar:

sudo apt-get update

Isso apenas atualizará essa lista, e esperamos fazer algo sobre a linha que está causando o erro. Tanto quanto eu sei, isso não deve estragar nada, mas eu não tenho 100% de certeza, então tente isso por sua conta e risco.

Espero que isso funcione (e que eu não tenha lhe dado um mau conselho) DeveloperNewb