无法获取http://archive.ubuntu.com/ubuntu/pool/main/g/grub2/grub-common 500内部服务器错误[IP：91.189.88.152 80]

Question

我正在尝试运行sudo apt-get upgrade并收到500 Internal Server Error [IP：91.189.88.152 80]。可能做错了什么？ sudo apt-get update正常运行，没有任何错误。

下面是source.list

#

# deb cdrom:[Ubuntu-Server 16.04.3 LTS _Xenial Xerus_ - Release amd64 (20170801)]/ xenial main restricted

#deb cdrom:[Ubuntu-Server 16.04.3 LTS _Xenial Xerus_ - Release amd64 (20170801)]/ xenial main restricted

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

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

## 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://archive.ubuntu.com/ubuntu/  xenial universe
# deb-src http://ng.archive.ubuntu.com/ubuntu/  xenial universe
deb http://archive.ubuntu.com/ubuntu/  xenial-updates universe
# deb-src http://ng.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://archive.ubuntu.com/ubuntu/  xenial multiverse
# deb-src http://ng.archive.ubuntu.com/ubuntu/  xenial multiverse
deb http://archive.ubuntu.com/ubuntu/  xenial-updates multiverse
# deb-src http://ng.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.
deb http://archive.ubuntu.com/ubuntu/  xenial-backports main restricted universe multiverse
# deb-src http://ng.archive.ubuntu.com/ubuntu/  xenial-backports main restricted universe 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  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 main restricted
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

下面是错误消息的屏幕截图