运行命令时出现以下错误sudo apt-get update，我发现了类似的问题，但它们对我没有帮助。我该如何解决这个问题？
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/trusty/Release Unable to find expected entry 'restricted/source/Sources' in Release file (Wrong sources.list entry or malformed file)
W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/trusty/Release Unable to find expected entry 'universe/source/Sources' in Release file (Wrong sources.list entry or malformed file)
E: Some index files failed to download. They have been ignored, or old ones used instead.
cat /etc/apt/sources.list
# deb cdrom:[Ubuntu 14.04.4 LTS _Trusty Tahr_ - Release amd64 (20160217.1)]/ trusty main restricted
deb-src http://archive.ubuntu.com/ubuntu trusty 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://in.archive.ubuntu.com/ubuntu/ trusty main restricted
deb-src http://in.archive.ubuntu.com/ubuntu/ trusty universe restricted multiverse main #Added by software-properties
## Major bug fix updates produced after the final release of the
## distribution.
deb http://in.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
deb-src http://in.archive.ubuntu.com/ubuntu/ trusty-updates universe restricted multiverse main #Added by software-properties
## N.B. 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://in.archive.ubuntu.com/ubuntu/ trusty universe
deb http://in.archive.ubuntu.com/ubuntu/ trusty-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://in.archive.ubuntu.com/ubuntu/ trusty multiverse
deb http://in.archive.ubuntu.com/ubuntu/ trusty-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.
deb http://in.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://in.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse #Added by software-properties
deb http://security.ubuntu.com/ubuntu trusty-security main restricted
deb-src http://security.ubuntu.com/ubuntu trusty-security universe restricted multiverse main #Added by software-properties
deb http://security.ubuntu.com/ubuntu trusty-security universe
deb http://security.ubuntu.com/ubuntu trusty-security multiverse
## 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 trusty partner
deb-src http://archive.canonical.com/ubuntu trusty partner
## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu trusty main
deb-src http://extras.ubuntu.com/ubuntu trusty main
#deb http://us.archive.ubuntu.com/ubuntu precise main universe
dig google.com
; <<>> DiG 9.9.5-3ubuntu0.7-Ubuntu <<>> google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 10513
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;google.com. IN A
;; ANSWER SECTION:
google.com. 52 IN A 216.58.197.46
google.com. 52 IN A 216.58.197.46
google.com. 52 IN A 216.58.197.46
;; Query time: 9 msec
;; SERVER: 127.0.1.1#53(127.0.1.1)
;; WHEN: Wed May 17 20:17:42 IST 2017
;; MSG SIZE rcvd: 87
我没有看到任何与http://archive.ubuntu.com/ubuntu/dists/trusty/Release它/etc/apt/sources.list实际来源有关的东西。
有人能建议一种解决此错误的方法吗？
答案1
我将您的 sources.list 与我们的一台可靠机器上的 sources.list 进行了比较。除了服务器的原产国之外，我看到的最大区别是您的 .list 仍然包含 cdrom 文件。我记得删除它是为了解决某种问题，也许是这个？
无论如何，测试起来很容易。打开“软件和更新”，取消选中最后一个框。单击“关闭”时，它将重新加载源，并告诉您是否有效。
