To fix the error first of all we do reset the repository by the following steps.
Reset your repositories like this:
IMPORTANT: First verify that you have software-properties-gtk installed (you can run software-properties-gtk -h to verify that you get a help-message)
Then, for safer side we will take a backup of sources.list file. To do so here I’m making a copy ofsources.list file,
- sudo mv /etc/apt/sources.list /etc/apt/sources.list.bak
- sudo software-properties-gtk
- Pick your options
- Update Ubuntu
Once everything is working, you can then delete your backup with sudo rm -rf /etc/apt/sources.list.bak.
Do tick all option in Software and Updates.