I run a Dual-boot Linux Mint 18.3 / Win7 system, and, lately in Linux, updating ends with the following error message:

"Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list.d/additional-repositories.list:1 and /etc/apt/sources.list.d/additional-repositories.list:2Target Packages (main/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list.d/additional-repositories.list:1 and /etc/apt/sources.list.d/additional-repositories.list:2Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list.d/additional-repositories.list:1 and /etc/apt/sources.list.d/additional-repositories.list:2Target Translations (main/i18n/Translation-en_AU) is configured multiple times in /etc/apt/sources.list.d/additional-repositories.list:1 and /etc/apt/sources.list.d/additional-repositories.list:2Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list.d/additional-repositories.list:1 and /etc/apt/sources.list.d/additional-repositories.list:2"

The download seems to proceed normally, and the packages seem to install normally. I will also occasionally get a message "unable to refresh the list of updates" (a red cross on the taskbar icon), but, if you open the update window and ask it to refresh the list, it does so normally except for the above error messages.
Can I get rid of these "multiple configurations" and, therefore, the error message, and, if so, how?

Can you post the sources.list ?

Dear Keruskerfuerst,
Yes, I will post sources.list, if I know what it is and where to find it.
Thanks,
Ron Anstis.

Moved: This thread is more suitable in <Linux Mint> and has been moved accordingly to help your thread/question get the exposure it deserves.

I think sources.list can be found here: /etc/apt/sources.list.

Dear Keruskerfuerst,
I have tried every way I can think of to access /etc/apt/sources.list. but all I get is answers as follows:
/etc/apt/sources.list.
bash: etc/apt/sources.list: No such file or directory

or,
ls /etc/apt/sources.list.
ls: cannot access '/etc/apt/sources.list.': No such file or directory

Do you know what other command I could use to try to access the file?

In Ubuntu and Mint, /etc/apt/sources.list can be read (and edited) "with sudo" and an editor.

Examples :
$ sudo gedit /etc/apt/sources.list
$ sudo leafpad /etc/apt/sources.list

Keruskerfuerst and knudfl,

gedit and leafpad didn't work, but xed gave me the following: "#deb cdrom:[Linux Mint 18.3 _Sylvia_ - Release amd64 20171124]/ xenial contrib main non-free".. Does this help?

Re #8.

One line ? The hash mark (#) means that the "cdrom" is commented out.

The /etc/apt/sources.list must be like
Ref. https://sites.google.com/site/easyli...ject/reserve-8
... Edit, and run 'sudo apt update'

-

To Keruskerfuerst and knudfl,
Thank you so much for your help - this one was truly beyond me!! I have followed the instructions on knudfl's last post, and found the posted web reference to be most helpful, and, after following the instructions, updating and installing the new kernel, all seems to be well, though I have only gone through one update. I'll keep an eye on it, but it is working at the moment!

Your question shows me, that you are not very experienced with Linux.
Just read the error output.

And try to solve with searching in Inet and Goooogle.
Next ask the question here.

And: search for Ubuntu book in the internet or buy a actual Ubuntu book.