我是 Ubuntu 新手，我遇到了无法打开软件中心的问题。屏幕右上角有一个红点，上面有一条水平白线。单击它时会显示以下内容；
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
我应该怎么做才能解决这个问题？
更新：我尝试更新并得到以下结果：
E: Malformed line 56 in source list /etc/apt/sources.list (dist parse)
E: The list of sources could not be read.
更新2：当我输入时cat /etc/apt/sources.list，我得到的返回结果是：
更新 3：我按照你说的做了，结果如下
~$ 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.
答案1
我对 Ubuntu 也不太了解，但似乎发生的情况是您的软件源列表已损坏（该列表是保存软件所有源的文件，因此如果您更新软件，它知道在哪里查找）。我会尝试打开终端并输入：
sudo apt-get update
这只会更新该列表，并希望对导致错误的行进行一些处理。据我所知，这不会弄乱任何东西，但我不能 100% 确定，所以尝试此操作需要您自担风险。
我希望这个方法有效（并且我没有给你坏建议） DeveloperNewb