Error while installing dependencies

[naviabbot]

OS - Debian 9

I've gotten past the DNS verification steps. However, once it supposedly finishes installing dependencies, I get the following:

Hit:1 http://security.debian.org/debian-security stretch/updates InRelease
Ign:2 http://http.us.debian.org/debian stretch InRelease
Hit:3 http://http.us.debian.org/debian stretch-updates InRelease
Get:4 http://security.debian.org stable/updates InRelease [65.4 kB]
Hit:5 http://http.us.debian.org/debian stretch Release
Hit:6 http://ftp.debian.org/debian stretch-backports InRelease
Ign:7 http://security.debian.org testing/updates InRelease
Get:8 http://ftp.de.debian.org/debian stable InRelease [121 kB]
Ign:10 http://security.debian.org testing/updates Release
Get:11 http://security.debian.org stable/updates/main amd64 Packages [201 kB]
Get:12 http://security.debian.org stable/updates/main Translation-en [108 kB]
Get:13 http://security.debian.org stable/updates/non-free amd64 Packages [552 B]
Get:14 http://security.debian.org stable/updates/non-free Translation-en [344 B]
Ign:15 http://security.debian.org testing/updates/main amd64 Packages
Get:16 http://ftp.de.debian.org/debian testing InRelease [116 kB]
Get:17 http://ftp.de.debian.org/debian stable/contrib Sources [43.1 kB]
Get:18 http://ftp.de.debian.org/debian stable/non-free Sources [85.9 kB]
Get:19 http://ftp.de.debian.org/debian stable/main Sources [7831 kB]
Ign:20 http://security.debian.org testing/updates/main all Packages
Ign:21 http://security.debian.org testing/updates/main Translation-en
Ign:22 http://security.debian.org testing/updates/contrib amd64 Packages
Ign:23 http://security.debian.org testing/updates/contrib all Packages
Get:24 http://ftp.de.debian.org/debian stable/main amd64 Packages [7905 kB]
Ign:25 http://security.debian.org testing/updates/contrib Translation-en
Get:26 http://ftp.de.debian.org/debian stable/main Translation-en [5969 kB]
Ign:27 http://security.debian.org testing/updates/non-free all Packages
Ign:28 http://security.debian.org testing/updates/non-free amd64 Packages
Get:29 http://ftp.de.debian.org/debian stable/contrib amd64 Packages [51.0 kB]
Get:30 http://ftp.de.debian.org/debian stable/contrib Translation-en [44.7 kB]
Get:31 http://ftp.de.debian.org/debian stable/non-free amd64 Packages [87.7 kB]
Get:32 http://ftp.de.debian.org/debian stable/non-free Translation-en [88.9 kB]
Get:33 http://ftp.de.debian.org/debian testing/main Sources [8112 kB]
Ign:34 http://security.debian.org testing/updates/non-free Translation-en
Get:35 http://ftp.de.debian.org/debian testing/non-free Sources [79.1 kB]
Get:36 http://ftp.de.debian.org/debian testing/contrib Sources [41.1 kB]
Get:37 http://ftp.de.debian.org/debian testing/main amd64 Packages [7693 kB]
Ign:15 http://security.debian.org testing/updates/main amd64 Packages
Ign:20 http://security.debian.org testing/updates/main all Packages
Get:38 http://ftp.de.debian.org/debian testing/main Translation-en [5881 kB]
Ign:21 http://security.debian.org testing/updates/main Translation-en
Get:39 http://ftp.de.debian.org/debian testing/contrib amd64 Packages [47.6 kB]
Get:40 http://ftp.de.debian.org/debian testing/contrib Translation-en [43.4 kB]
Get:41 http://ftp.de.debian.org/debian testing/non-free amd64 Packages [91.6 kB]
Get:42 http://ftp.de.debian.org/debian testing/non-free Translation-en [88.9 kB]
Ign:22 http://security.debian.org testing/updates/contrib amd64 Packages
Ign:23 http://security.debian.org testing/updates/contrib all Packages
Ign:25 http://security.debian.org testing/updates/contrib Translation-en
Ign:27 http://security.debian.org testing/updates/non-free all Packages
Ign:28 http://security.debian.org testing/updates/non-free amd64 Packages
Ign:34 http://security.debian.org testing/updates/non-free Translation-en
Ign:15 http://security.debian.org testing/updates/main amd64 Packages
Ign:20 http://security.debian.org testing/updates/main all Packages
Ign:21 http://security.debian.org testing/updates/main Translation-en
Ign:22 http://security.debian.org testing/updates/contrib amd64 Packages
Ign:23 http://security.debian.org testing/updates/contrib all Packages
Ign:25 http://security.debian.org testing/updates/contrib Translation-en
Ign:27 http://security.debian.org testing/updates/non-free all Packages
Ign:28 http://security.debian.org testing/updates/non-free amd64 Packages
Ign:34 http://security.debian.org testing/updates/non-free Translation-en
Ign:15 http://security.debian.org testing/updates/main amd64 Packages
Ign:20 http://security.debian.org testing/updates/main all Packages
Ign:21 http://security.debian.org testing/updates/main Translation-en
Ign:22 http://security.debian.org testing/updates/contrib amd64 Packages
Ign:23 http://security.debian.org testing/updates/contrib all Packages
Ign:25 http://security.debian.org testing/updates/contrib Translation-en
Ign:27 http://security.debian.org testing/updates/non-free all Packages
Ign:28 http://security.debian.org testing/updates/non-free amd64 Packages
Ign:34 http://security.debian.org testing/updates/non-free Translation-en
Ign:15 http://security.debian.org testing/updates/main amd64 Packages
Ign:20 http://security.debian.org testing/updates/main all Packages
Ign:21 http://security.debian.org testing/updates/main Translation-en
Ign:22 http://security.debian.org testing/updates/contrib amd64 Packages
Ign:23 http://security.debian.org testing/updates/contrib all Packages
Ign:25 http://security.debian.org testing/updates/contrib Translation-en
Ign:27 http://security.debian.org testing/updates/non-free all Packages
Ign:28 http://security.debian.org testing/updates/non-free amd64 Packages
Ign:34 http://security.debian.org testing/updates/non-free Translation-en
Err:15 http://security.debian.org testing/updates/main amd64 Packages
  404  Not Found [IP: 151.101.184.204 80]
Ign:20 http://security.debian.org testing/updates/main all Packages
Ign:21 http://security.debian.org testing/updates/main Translation-en
Ign:22 http://security.debian.org testing/updates/contrib amd64 Packages
Ign:23 http://security.debian.org testing/updates/contrib all Packages
Ign:25 http://security.debian.org testing/updates/contrib Translation-en
Ign:27 http://security.debian.org testing/updates/non-free all Packages
Ign:28 http://security.debian.org testing/updates/non-free amd64 Packages
Ign:34 http://security.debian.org testing/updates/non-free Translation-en
Fetched 44.8 MB in 10s (4302 kB/s)
Reading package lists... Done
W: The repository 'http://security.debian.org testing/updates 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://security.debian.org/dists/testing/updates/main/binary-amd64/Packages  404  Not Found [IP: 151.101.184.204 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.