Hope you can help with my queries:
Currently I have a Pi2+ running NOOBS Raspian with Razberry daughter card with around 70 devices.
I am stuck upgrading the firmware from V2.3.7 as the repository does not support the UI. ( =I have been slow on the update due to it never working for me but now know I need to bring the setup into this decade).
Naturally I do not want to break any part of my setup as tht would be soul-destroying.
My queries are:
1 - how can I upgrade to the latest possible version with my current setup, then
2 - what would be my vest option to migrate the whole setup onto new hardware safely?
Below is the terminal response from a failed update.
Thank you in advance.

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pi@raspberrypi ~ $ sudo apt-get update && apt-get upgrade
Get:1 http://archive.raspberrypi.org jessie InRelease [22.9 kB]
Get:2 http://archive.raspberrypi.org jessie/main Sources [57.1 kB]
Get:3 http://archive.raspberrypi.org jessie/ui Sources [17.1 kB]
Get:4 http://archive.raspberrypi.org jessie/main armhf Packages [170 kB]
Get:5 http://archive.raspberrypi.org jessie/ui armhf Packages [58.6 kB]
Ign http://archive.raspberrypi.org jessie/main Translation-en_GB
Ign http://archive.raspberrypi.org jessie/main Translation-en
Ign http://archive.raspberrypi.org jessie/ui Translation-en_GB
Ign http://archive.raspberrypi.org jessie/ui Translation-en
Ign http://mirrordirector.raspbian.org jessie InRelease
Ign http://mirrordirector.raspbian.org jessie Release.gpg
Ign http://mirrordirector.raspbian.org jessie Release
Err http://mirrordirector.raspbian.org jessie/main armhf Packages
404 Not Found [IP: 93.93.128.193 80]
Err http://mirrordirector.raspbian.org jessie/contrib armhf Packages
404 Not Found [IP: 93.93.128.193 80]
Err http://mirrordirector.raspbian.org jessie/non-free armhf Packages
404 Not Found [IP: 93.93.128.193 80]
Err http://mirrordirector.raspbian.org jessie/rpi armhf Packages
404 Not Found [IP: 93.93.128.193 80]
Ign http://mirrordirector.raspbian.org jessie/contrib Translation-en_GB
Ign http://mirrordirector.raspbian.org jessie/contrib Translation-en
Ign http://mirrordirector.raspbian.org jessie/main Translation-en_GB
Ign http://mirrordirector.raspbian.org jessie/main Translation-en
Ign http://mirrordirector.raspbian.org jessie/non-free Translation-en_GB
Ign http://mirrordirector.raspbian.org jessie/non-free Translation-en
Ign http://mirrordirector.raspbian.org jessie/rpi Translation-en_GB
Ign http://mirrordirector.raspbian.org jessie/rpi Translation-en
Fetched 326 kB in 51s (6,352 B/s)
W: Failed to fetch http://mirrordirector.raspbian.org/rasp ... f/Packages 404 Not Found [IP: 93.93.128.193 80]
W: Failed to fetch http://mirrordirector.raspbian.org/rasp ... f/Packages 404 Not Found [IP: 93.93.128.193 80]
W: Failed to fetch http://mirrordirector.raspbian.org/rasp ... f/Packages 404 Not Found [IP: 93.93.128.193 80]
W: Failed to fetch http://mirrordirector.raspbian.org/rasp ... f/Packages 404 Not Found [IP: 93.93.128.193 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.
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