See apt-secure(8) manpage for repository creation and user configuration details

Desktop
1

I run the update on Ubuntu 16.04 LTE:

sudo apt-get update && sudo apt-get upgrade

My problem is:
Err:9 Index of /ffdiaporamateam/stable/ubuntu bionic Release
404 Not Found [IP: 91.189.95.83 80]
Reading package lists… Done
E: The repository ‘Index of /ffdiaporamateam/stable/ubuntu bionic Release’ does not have a Release file.
N: Updating from such a repository can’t be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Can you help me ?

Thanks.

2

This site is for the co-ordination of the Ubuntu project(s), and not support.

For Ubuntu Support options, there are many listed at https://community.ubuntu.com/t/finding-help/712

(a quick look showed that PPA does not support bionic (18.04) having it’s last update in 2014 (trusty)).