New question #675990 on Yade: https://answers.launchpad.net/yade/+question/675990
Hello, I am installing Yade source code on Ubuntu-16.04. when I update the software, the warning as following: W: The repository 'http://ppa.launchpad.net/yade-users/external/ubuntu xenial Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. E: Failed to fetch http://ppa.launchpad.net/yade-users/external/ubuntu/dists/xenial/main/binary-amd64/Packages 404 Not Found E: Some index files failed to download. They have been ignored, or old ones used instead. what's the problem of this and how to solve it? Thanks! my source.list is: # deb cdrom:[Ubuntu 16.04.4 LTS _Xenial Xerus_ - Release amd64 (20180228)]/ xenial main restricted # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://cn.archive.ubuntu.com/ubuntu/ xenial main restricted # deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial main restricted ## Major bug fix updates produced after the final release of the ## distribution. deb http://cn.archive.ubuntu.com/ubuntu/ xenial-updates main restricted # deb-src http://cn.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://cn.archive.ubuntu.com/ubuntu/ xenial universe # deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial universe deb http://cn.archive.ubuntu.com/ubuntu/ xenial-updates universe # deb-src http://cn.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://cn.archive.ubuntu.com/ubuntu/ xenial multiverse # deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial multiverse deb http://cn.archive.ubuntu.com/ubuntu/ xenial-updates multiverse # deb-src http://cn.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://cn.archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse # deb-src http://cn.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 deb http://www.yade-dem.org/packages/ xenial/ -- You received this question notification because your team yade-users is an answer contact for Yade. _______________________________________________ Mailing list: https://launchpad.net/~yade-users Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp

