error 404 when updating

[kazooie911]

i installed a fresh copy of 15:10 on a macbook. and when i go to update it it says failed both in terminal and software & updates

[coffeecat]

Ubuntu 15.10 reached end of life over 2 years ago and the repositories are closed. That is why you cannot update it. Why did you install an obsolete release?

You need to install something that is still supported. I would suggest 18.04, the latest long-term support version that will be supported until 2023.