需要安装不受信任的包吗?

我昨天尝试安装VLC播放器,我得到了Requires installation of untrusted packagesRequires installation of untrusted packages错误。 我搜索了几个小时来找到这个问题的解决方案,最后发现了一个建议说要更改服务器以便从中下载更新。 我这样做了,当我点击Update Manager中的“Check”时,它给了我404错误。 我尝试将我的服务器切换回主服务器(之后,其他几个),但我现在仍然收到404错误: 在此处输入图像描述

我下载或更新时遇到的另一个错误: 在此处输入图像描述

编辑: cat /etc/apt/sources.list输出:

 deb-src http://us.archive.ubuntu.com/ubuntu/ precise 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://us.archive.ubuntu.com/ubuntu/ precise main restricted multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise multiverse universe #Added by software-properties ## Major bug fix updates produced after the final release of the ## distribution. deb http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates restricted main multiverse universe #Added by software-properties ## NB software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://us.archive.ubuntu.com/ubuntu/ precise universe deb http://us.archive.ubuntu.com/ubuntu/ precise-updates universe ## NB 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. ## NB 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. deb http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse #Added by software-properties deb http://us.archive.ubuntu.com/ubuntu/ precise-security main restricted multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise-security restricted main multiverse universe #Added by software-properties deb http://us.archive.ubuntu.com/ubuntu/ precise-security universe ## 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 precise partner deb-src http://archive.canonical.com/ubuntu precise partner ## This software is not part of Ubuntu, but is offered by third-party ## developers who want to ship their latest software. 

根据您在上一个答案的评论部分中粘贴的错误,我有另一种可能的解决方案:

 sudo apt-get clean cd /var/lib/apt sudo mv lists lists.old sudo mkdir -p lists/partial sudo apt-get clean sudo apt-get update 

这将重建缓存。
礼貌: http //ubuntuforums.org/showthread.php? t = 1983220#8

此链接可能有所帮助 。 它解决了一个非常类似的问题。

基本上,你打开一个终端并键入sudo apt-get update && sudo apt-get upgrade 。 这样做对我而言。

在我的情况下(Ubuntu 13.10),接受的答案对我没有帮助,但我能够通过命令行而不是通过软件更新程序解决问题更新(如果有其他人遇到此问题)。

 sudo aptitude upgrade 

向我展示了来自不受信任的来源(Google的音乐管理器)的特定软件包,并询问我是否要接受并升级。

尝试更新系统指示器时,我遇到了完全相同的错误。

在我的情况下,这是因为缺少GPG密钥。 这里有一个答案,它将指示您安装PPA管理器,它可以尝试导入所有丢失的密钥。 我做了这个,并没有给我任何确认丢失的密钥被导入但我之后运行更新,它安装得很好。

在这种情况下,我必须说这是一个可怕的(无用的)错误消息。

https://askubuntu.com/a/386003/11929