I know OMV isn't fit and forget but I've just left mine for a few years. I now get errors when checking for updates and plugins.
Error message below
Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C.UTF-8; apt-get update 2>&1' with exit code '100': Get:1 file:/var/cache/openmediavault/archives InRelease Ign:1 file:/var/cache/openmediavault/archives InRelease Get:2 file:/var/cache/openmediavault/archives Release Ign:2 file:/var/cache/openmediavault/archives Release Get:3 file:/var/cache/openmediavault/archives Packages Ign:3 file:/var/cache/openmediavault/archives Packages Get:4 file:/var/cache/openmediavault/archives Translation-en Ign:4 file:/var/cache/openmediavault/archives Translation-en Get:3 file:/var/cache/openmediavault/archives Packages Ign:3 file:/var/cache/openmediavault/archives Packages Get:4 file:/var/cache/openmediavault/archives Translation-en Ign:4 file:/var/cache/openmediavault/archives Translation-en Get:3 file:/var/cache/openmediavault/archives Packages Ign:3 file:/var/cache/openmediavault/archives Packages Get:4 file:/var/cache/openmediavault/archives Translation-en Ign:4 file:/var/cache/openmediavault/archives Translation-en Get:3 file:/var/cache/openmediavault/archives Packages Ign:3 file:/var/cache/openmediavault/archives Packages Get:4 file:/var/cache/openmediavault/archives Translation-en Ign:4 file:/var/cache/openmediavault/archives Translation-en Get:3 file:/var/cache/openmediavault/archives Packages Ign:3 file:/var/cache/openmediavault/archives Packages Get:4 file:/var/cache/openmediavault/archives Translation-en Ign:4 file:/var/cache/openmediavault/archives Translation-en Get:3 file:/var/cache/openmediavault/archives Packages Get:4 file:/var/cache/openmediavault/archives Translation-en Ign:4 file:/var/cache/openmediavault/archives Translation-en Ign:5 http://security.debian.org/debian-security stretch/updates InRelease Err:6 http://security.debian.org/debian-security stretch/updates Release 404 Not Found Ign:7 http://ftp.uk.debian.org/debian stretch InRelease Ign:8 http://ftp.uk.debian.org/debian stretch-updates InRelease Err:9 http://ftp.uk.debian.org/debian stretch Release 404 Not Found Err:10 http://ftp.uk.debian.org/debian stretch-updates Release 404 Not Found Hit:11 http://packages.openmediavault.org/public arrakis InRelease Ign:12 http://httpredir.debian.org/debian stretch-backports InRelease Ign:13 http://httpredir.debian.org/debian stretch-backports Release Ign:14 http://httpredir.debian.org/debian stretch-backports/main all Packages Ign:15 http://httpredir.debian.org/debian stretch-backports/main amd64 Packages Ign:16 http://httpredir.debian.org/debian stretch-backports/main Translation-en Ign:17 http://httpredir.debian.org/debian stretch-backports/contrib amd64 Packages Get:18 https://openmediavault.github.io/packages arrakis InRelease [12.8 kB] Ign:19 http://httpredir.debian.org/debian stretch-backports/contrib all Packages Ign:20 http://httpredir.debian.org/debian stretch-backports/contrib Translation-en Ign:21 http://httpredir.debian.org/debian stretch-backports/non-free amd64 Packages Ign:22 http://httpredir.debian.org/debian stretch-backports/non-free all Packages Ign:23 http://httpredir.debian.org/debian stretch-backports/non-free Translation-en Ign:14 http://httpredir.debian.org/debian stretch-backports/main all Packages Ign:15 http://httpredir.debian.org/debian stretch-backports/main amd64 Packages Ign:16 http://httpredir.debian.org/debian stretch-backports/main Translation-en Ign:17 http://httpredir.debian.org/debian stretch-backports/contrib amd64 Packages Ign:19 http://httpredir.debian.org/debian stretch-backports/contrib all Packages Ign:20 http://httpredir.debian.org/debian stretch-backports/contrib Translation-en Ign:21 http://httpredir.debian.org/debian stretch-backports/non-free amd64 Packages Ign:22 http://httpredir.debian.org/debian stretch-backports/non-free all Packages Ign:23 http://httpredir.debian.org/debian stretch-backports/non-free Translation-en Ign:14 http://httpredir.debian.org/debian stretch-backports/main all Packages Ign:15 http://httpredir.debian.org/debian stretch-backports/main amd64 Packages Ign:16 http://httpredir.debian.org/debian stretch-backports/main Translation-en Ign:17 http://httpredir.debian.org/debian stretch-backports/contrib amd64 Packages Ign:19 http://httpredir.debian.org/debian stretch-backports/contrib all Packages Ign:20 http://httpredir.debian.org/debian stretch-backports/contrib Translation-en Ign:21 http://httpredir.debian.org/debian stretch-backports/non-free amd64 Packages Ign:22 http://httpredir.debian.org/debian stretch-backports/non-free all Packages Ign:23 http://httpredir.debian.org/debian stretch-backports/non-free Translation-en Ign:14 http://httpredir.debian.org/debian stretch-backports/main all Packages Ign:15 http://httpredir.debian.org/debian stretch-backports/main amd64 Packages Ign:16 http://httpredir.debian.org/debian stretch-backports/main Translation-en Ign:17 http://httpredir.debian.org/debian stretch-backports/contrib amd64 Packages Ign:19 http://httpredir.debian.org/debian stretch-backports/contrib all Packages Ign:20 http://httpredir.debian.org/debian stretch-backports/contrib Translation-en Ign:21 http://httpredir.debian.org/debian stretch-backports/non-free amd64 Packages Ign:22 http://httpredir.debian.org/debian stretch-backports/non-free all Packages Ign:23 http://httpredir.debian.org/debian stretch-backports/non-free Translation-en Ign:14 http://httpredir.debian.org/debian stretch-backports/main all Packages Ign:15 http://httpredir.debian.org/debian stretch-backports/main amd64 Packages Ign:16 http://httpredir.debian.org/debian stretch-backports/main Translation-en Ign:17 http://httpredir.debian.org/debian stretch-backports/contrib amd64 Packages Ign:19 http://httpredir.debian.org/debian stretch-backports/contrib all Packages Ign:20 http://httpredir.debian.org/debian stretch-backports/contrib Translation-en Ign:21 http://httpredir.debian.org/debian stretch-backports/non-free amd64 Packages Ign:22 http://httpredir.debian.org/debian stretch-backports/non-free all Packages Ign:23 http://httpredir.debian.org/debian stretch-backports/non-free Translation-en Ign:14 http://httpredir.debian.org/debian stretch-backports/main all Packages Err:15 http://httpredir.debian.org/debian stretch-backports/main amd64 Packages 404 Not Found Ign:16 http://httpredir.debian.org/debian stretch-backports/main Translation-en Ign:17 http://httpredir.debian.org/debian stretch-backports/contrib amd64 Packages Ign:19 http://httpredir.debian.org/debian stretch-backports/contrib all Packages Ign:20 http://httpredir.debian.org/debian stretch-backports/contrib Translation-en Ign:21 http://httpredir.debian.org/debian stretch-backports/non-free amd64 Packages Ign:22 http://httpredir.debian.org/debian stretch-backports/non-free all Packages Ign:23 http://httpredir.debian.org/debian stretch-backports/non-free Translation-en Exception ignored in: <function WeakValueDictionary.__init__.<locals>.remove at 0x7f7ed5788a60> Traceback (most recent call last): File "/usr/lib/python3.5/weakref.py", line 117, in remove TypeError: 'NoneType' object is not callable Exception ignored in: <function WeakValueDictionary.__init__.<locals>.remove at 0x7f7ed5788a60> Traceback (most recent call last): File "/usr/lib/python3.5/weakref.py", line 117, in remove TypeError: 'NoneType' object is not callable Reading package lists... E: The repository 'http://security.debian.org/debian-security stretch/updates Release' does no longer have a Release file. E: The repository 'http://ftp.uk.debian.org/debian stretch Release' does no longer have a Release file. E: The repository 'http://ftp.uk.debian.org/debian stretch-updates Release' does no longer have a Release file. W: The repository 'http://httpredir.debian.org/debian stretch-backports Release' does not have a Release file.
Obviously I have no idea what any of that means but id like to update to version 7 possibly.
What's the best way forward please??
Many Thanks
James