I get an error when I try to download any apps from the terminal
and the app center or running sudo apt-get update.
The error message is:
E: Type '<!DOCTYPE' is not known on line 1 in source list /etc/apt/sources.list.d/medibuntu.list
E: The list of sources could not be read.
The error message suggests you have a broken medibuntu.list file. I would assume you have tried to add the Medibuntu repository at some point and something has gone wrong.
You should be able to restore functionality in the terminal by removing that file with the following command:
sudo rm /etc/apt/sources.list.d/medibuntu.list
After that, if you run a sudo apt update everything should be back to normal.
I have similar problem, tried and got this: AppCenter Failed to Fetch Updates
Then it shows details:
W: Skipping acquire of configured file 'main/binary-armhf/Packages' as repository 'http://packages.elementary.io/appcenter xenial InRelease' doesn't support architecture 'armhf'
