E: The list of sources could not be read. FIX
ok to fix it it's very simple:
1- sudo su
2- cd /etc/apt/sources.list.d/
3- ls
4- now look for any file has the word "webmin" or any name of app that you doesn't use or doesn't work
5- rm "name of file" "space" "name of the other file you if there is"
6- apt update
7- apt upgrade
8- congratulations problem solved
If you need assistance with your projects feel free to email me at info@airgad.com or whatsapp Jesse stay safe!