Synaptic error on opening

What is the output of:

cat -n /etc/apt/sources.list| grep 5

Thanks

Searching on the web fount this “sudo -H gedit /etc/apt/sources.list” to fix entry 55 I execute this and the command sudo apt-get update it took long time to complete.
Now I can get into Synaptic but Repositories Software & Updates are in a mess, just had a Software Update when running gave errors I stop to first fix Software & Updates.
Terminal output:

luis@luis-Ubuntu-16:~$ cat -n /etc/apt/sources.list| grep 5
     5 # deb http://mirror.wiru.co.za/ubuntu/ xenial main restricted
    15 ## your rights to use the software. Also, please note that software in
    25 ## your rights to use the software. Also, please note that software in
    35 ## newer versions of some applications which may provide useful features.
    45 deb-src http://archive.canonical.com/ubuntu xenial partner
    50 # deb-src http://security.ubuntu.com/ubuntu xenial-security universe
    51 deb http://ubuntu.saix.net/ubuntu-archive/ xenial-security multiverse
    52 # deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
    53 deb http://archive.ubuntu.com/ubuntu xenial main universe restricted multiverse
    54 deb-src http://archive.ubuntu.com/ubuntu xenial multiverse universe restricted main #Added by software-properties
    55 deb http://ubuntu.saix.net/ubuntu-archive/ xenial universe
luis@luis-Ubuntu-16:~$

For diagnostic purposes please open a terminal window and execute the commands

uname -a
lsb_release -crid
sudo apt-get update

and then copy/paste all output into this question document that we can check the results.

Have notification of new Software Update.

luis@luis-Ubuntu-16:~$ uname -a
Linux luis-Ubuntu-16 4.4.0-130-generic #156-Ubuntu SMP Thu Jun 14 08:51:45 UTC 2018 i686 i686 i686 GNU/Linux
luis@luis-Ubuntu-16:~$ lsb_release -crid
Distributor ID: Ubuntu
Description: Ubuntu 16.04.4 LTS
Release: 16.04
Codename: xenial
luis@luis-Ubuntu-16:~$ sudo apt-get update
[sudo] password for luis:
Hit:1 http://ubuntu.saix.net/ubuntu-archive xenial InRelease
Get:2 http://ubuntu.saix.net/ubuntu-archive xenial-updates InRelease [109 kB]
Hit:3 http://archive.canonical.com/ubuntu xenial InRelease
Get:4 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]
Hit:5 http://ubuntu.saix.net/ubuntu-archive xenial-security InRelease
Hit:6 http://archive.ubuntu.com/ubuntu xenial InRelease
Get:7 http://archive.ubuntu.com/ubuntu xenial-updates/main i386 Packages [757 kB]
Get:8 http://archive.ubuntu.com/ubuntu xenial-updates/universe i386 Packages [619 kB]
Fetched 1,595 kB in 9s (174 kB/s)
Reading package lists... Done
luis@luis-Ubuntu-16:~$

Looks OK. Is synaptic happy now?

Synaptic is working but still problems.
Repositories Software & Updates Other Software some of entries are missing don’t know if
is going to cause problems.
Please advise
Thank your

"Synaptic is working but still problems"
Please provide details about the problems that you see in synaptic.

One problem is in Repositories Software & Updates Other Software there are only two entries

http://ubuntu.saix.net/ubuntu-archive/ xenial mutiverse
http://ubuntu.saix.net/ubuntu-archive/ xenial-updates multiverse

I am sure there was about 6 entries before.
The other problems are about my question 672550 that is for later.

What is the full output of the commands

cat -n /etc/apt/sources.list
grep deb /etc/apt/sources.list.d/*.list

luis@luis-Ubuntu-16:~$ cat -n /etc/apt/sources.list
     1 # deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release i386 (20160420.1)]/ xenial main restricted
     2
     3 # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
     4 # newer versions of the distribution.
     5 # deb http://mirror.wiru.co.za/ubuntu/ xenial main restricted
     6 # deb-src http://za.archive.ubuntu.com/ubuntu/ xenial main restricted
     7
     8 ## Major bug fix updates produced after the final release of the
     9 ## distribution.
    10 deb http://archive.ubuntu.com/ubuntu xenial-updates main restricted
    11 # deb-src http://za.archive.ubuntu.com/ubuntu/ xenial-updates main restricted
    12
    13 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    14 ## team, and may not be under a free licence. Please satisfy yourself as to
    15 ## your rights to use the software. Also, please note that software in
    16 ## universe WILL NOT receive any review or updates from the Ubuntu security
    17 ## team.
    18 # deb http://mirror.wiru.co.za/ubuntu/ xenial universe
    19 # deb-src http://za.archive.ubuntu.com/ubuntu/ xenial universe
    20 deb http://archive.ubuntu.com/ubuntu xenial-updates universe
    21 # deb-src http://za.archive.ubuntu.com/ubuntu/ xenial-updates universe
    22
    23 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    24 ## team, and may not be under a free licence. Please satisfy yourself as to
    25 ## your rights to use the software. Also, please note that software in
    26 ## multiverse WILL NOT receive any review or updates from the Ubuntu
    27 ## security team.
    28 deb http://ubuntu.saix.net/ubuntu-archive/ xenial multiverse
    29 # deb-src http://za.archive.ubuntu.com/ubuntu/ xenial multiverse
    30 deb http://ubuntu.saix.net/ubuntu-archive/ xenial-updates multiverse
    31 # deb-src http://za.archive.ubuntu.com/ubuntu/ xenial-updates multiverse
    32
    33 ## N.B. software from this repository may not have been tested as
    34 ## extensively as that contained in the main release, although it includes
    35 ## newer versions of some applications which may provide useful features.
    36 ## Also, please note that software in backports WILL NOT receive any review
    37 ## or updates from the Ubuntu security team.
    38 # deb-src http://za.archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
    39
    40 ## Uncomment the following two lines to add software from Canonical's
    41 ## 'partner' repository.
    42 ## This software is not part of Ubuntu, but is offered by Canonical and the
    43 ## respective vendors as a service to Ubuntu users.
    44 deb http://archive.canonical.com/ubuntu xenial partner
    45 deb-src http://archive.canonical.com/ubuntu xenial partner
    46
    47 deb http://ubuntu.saix.net/ubuntu-archive/ xenial-security main restricted
    48 # deb-src http://security.ubuntu.com/ubuntu xenial-security main restricted
    49 deb http://ubuntu.saix.net/ubuntu-archive/ xenial-security universe
    50 # deb-src http://security.ubuntu.com/ubuntu xenial-security universe
    51 deb http://ubuntu.saix.net/ubuntu-archive/ xenial-security multiverse
    52 # deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
    53 deb http://archive.ubuntu.com/ubuntu xenial main universe restricted multiverse
    54 deb-src http://archive.ubuntu.com/ubuntu xenial multiverse universe restricted main #Added by software-properties
    55 deb http://ubuntu.saix.net/ubuntu-archive/ xenial universe
    56 deb http://security.ubuntu.com/ubuntu/ xenial-security main restricted universe multiverse
    57 deb http://archive.ubuntu.com/ubuntu xenial-backports main restricted universe multiverse
luis@luis-Ubuntu-16:~$ grep deb /etc/apt/sources.list.d/*.list
/etc/apt/sources.list.d/bit-team-ubuntu-testing-xenial.list:# deb http://ppa.launchpad.net/bit-team/testing/ubuntu xenial main
/etc/apt/sources.list.d/bit-team-ubuntu-testing-xenial.list:# deb-src http://ppa.launchpad.net/bit-team/testing/ubuntu xenial main
/etc/apt/sources.list.d/google-earth.list:# deb http://dl.google.com/linux/earth/deb/ stable main
/etc/apt/sources.list.d/jonathonf-ubuntu-backports-xenial.list:# deb http://ppa.launchpad.net/jonathonf/backports/ubuntu xenial main
/etc/apt/sources.list.d/jonathonf-ubuntu-backports-xenial.list:# deb-src http://ppa.launchpad.net/jonathonf/backports/ubuntu xenial main
/etc/apt/sources.list.d/librecad-dev-ubuntu-librecad-daily-xenial.list:# deb http://ppa.launchpad.net/librecad-dev/librecad-daily/ubuntu xenial main
/etc/apt/sources.list.d/librecad-dev-ubuntu-librecad-daily-xenial.list:# deb-src http://ppa.launchpad.net/librecad-dev/librecad-daily/ubuntu xenial main
/etc/apt/sources.list.d/librecad-dev-ubuntu-librecad-stable-xenial.list:# deb http://ppa.launchpad.net/librecad-dev/librecad-stable/ubuntu xenial main
/etc/apt/sources.list.d/librecad-dev-ubuntu-librecad-stable-xenial.list:# deb-src http://ppa.launchpad.net/librecad-dev/librecad-stable/ubuntu xenial main
/etc/apt/sources.list.d/libreoffice-ubuntu-libreoffice-5-4-xenial.list:# deb http://ppa.launchpad.net/libreoffice/libreoffice-5-4/ubuntu xenial main
/etc/apt/sources.list.d/libreoffice-ubuntu-libreoffice-5-4-xenial.list:# deb-src http://ppa.launchpad.net/libreoffice/libreoffice-5-4/ubuntu xenial main
/etc/apt/sources.list.d/qbittorrent-team-ubuntu-qbittorrent-stable-xenial.list:# deb http://ppa.launchpad.net/qbittorrent-team/qbittorrent-stable/ubuntu xenial main
/etc/apt/sources.list.d/qbittorrent-team-ubuntu-qbittorrent-stable-xenial.list:# deb-src http://ppa.launchpad.net/qbittorrent-team/qbittorrent-stable/ubuntu xenial main
luis@luis-Ubuntu-16:~$

Thanks Manfred Hampl, that solved my question.