AppCentre fails to fetch updates; sudo apt update gives several errors

Question

I can't update my installation anymore and I have no idea what I've done to it. I keep getting these errors every time I attempt to update my installation using the AppCentre or trying updating my package lists. I've tried all the solutions suggested on the other posts with no success.

Answer 1

It looks as though something has replaced the version codename incorrectly in your apt source files (i.e. /etc/apt/sources.list and the other files in /etc/apt/sources.list.d/)

It is likely that some instructions you followed to add a PPA inadvertently caused this, or one of the packages you installed from one of those PPAs did this automatically.

If you are running Juno or Hera (5.0 or 5.1)

You should be able to fix this by replacing all instances of juno or hera with bionic in /etc/apt/sources.list and all of the files inside /etc/apt/sources.list.d/

If you are running Loki (0.4)

You should be able to fix this by replacing all instances of loki with xenial in /etc/apt/sources.list and all of the files inside /etc/apt/sources.list.d/

Further Information

Where possible, it is recommended to install 3rd party apps like Brave via their Snap packaging format (there's an app called Snaptastic in the AppCenter to help with this). Adding PPAs is essentially giving the owner of that PPA root access to your system, and can lead to issues like this if they are not configured properly.

Answer 2

In my case, i install ubuntu-make following ppa instructions: https://github.com/ubuntu/ubuntu-make

I could solve my issue by run:

sudo nano /etc/apt/sources.list

and comment ( put a hastag (#)) before this line:

"deb cdrom:[elementary OS 0.4.1 Loki - Stable amd64 (20180214)]/ xenial contrib main non-free".

later save.