I still have this issue, any solutions?
this is my content of /etc/apt/source.list.d/elasticsearch.list
deb https://artifacts.elastic.co/packages/6.x/apt stable main
apt-get update -o Debug::pkgProblemResolver=true -o Debug::pkgDPkgPM=true
`Hit:1 http://security.debian.org/debian-security stretch/updates InRelease
Ign:2 http://deb.debian.org/debian stretch InRelease
Hit:3 http://deb.debian.org/debian stretch-updates InRelease
Ign:4 https://artifacts.elastic.co/packages/6.x/apt stable InRelease
Hit:5 http://deb.debian.org/debian stretch Release
Ign:6 https://artifacts.elastic.co/packages/6.x/apt stable Release
Ign:7 https://artifacts.elastic.co/packages/6.x/apt stable/main all Packages
Ign:8 https://artifacts.elastic.co/packages/6.x/apt stable/main amd64 Packages
Ign:9 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en
Ign:10 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en_US
Ign:7 https://artifacts.elastic.co/packages/6.x/apt stable/main all Packages
Ign:8 https://artifacts.elastic.co/packages/6.x/apt stable/main amd64 Packages
Ign:9 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en
Ign:10 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en_US
Ign:7 https://artifacts.elastic.co/packages/6.x/apt stable/main all Packages
Ign:8 https://artifacts.elastic.co/packages/6.x/apt stable/main amd64 Packages
Ign:9 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en
Ign:10 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en_US
Ign:7 https://artifacts.elastic.co/packages/6.x/apt stable/main all Packages
Ign:8 https://artifacts.elastic.co/packages/6.x/apt stable/main amd64 Packages
Ign:9 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en
Ign:10 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en_US
Hit:11 http://packages.treasuredata.com/3/debian/stretch stretch InRelease
Ign:7 https://artifacts.elastic.co/packages/6.x/apt stable/main all Packages
Ign:8 https://artifacts.elastic.co/packages/6.x/apt stable/main amd64 Packages
Ign:9 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en
Ign:10 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en_US
Ign:7 https://artifacts.elastic.co/packages/6.x/apt stable/main all Packages
Err:8 https://artifacts.elastic.co/packages/6.x/apt stable/main amd64 Packages
Ign:9 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en
Ign:10 https://artifacts.elastic.co/packages/6.x/apt stable/main Translation-en_US
Hit:12 http://repo.percona.com/percona/apt stretch InRelease
Hit:13 http://repo.zabbix.com/zabbix/3.4/debian stretch InRelease
Hit:14 http://repo.percona.com/prel/apt stretch InRelease
Hit:16 http://repo.zabbix.com/zabbix/4.0/debian stretch InRelease
Reading package lists... Done
W: The repository 'https://artifacts.elastic.co/packages/6.x/apt stable 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 https://artifacts.elastic.co/packages/6.x/apt/dists/stable/main/binary-amd64/Packages
E: Some index files failed to download. They have been ignored, or old ones used instead.`