I tested network-manager 1.44.2-1ubuntu1.1 inside a Mantic LXD container. Package installation/upgrade and Netplan migration of (valid) connection profiles worked nicely, according to the "Test Plan": # Previous version of NM is installed root@mm-nm-sru:~# dpkg -l network-manager Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-===============-===============-============-========================================================= ii network-manager 1.44.2-1ubuntu1 amd64 network management framework (daemon and userspace tools) # Creating test files root@mm-nm-sru:~# cat /etc/NetworkManager/system-connections/UPTOWN.guests [connection] id=UPTOWN.guests uuid=491fa5c8-68ef-4140-8679-dca422f5c262 type=wifi [wifi] ssid=UPTOWN.guests mode=infrastructure mac-address=E0:9D:31:09:84:54 [ipv6] method=auto [ipv4] method=auto root@mm-nm-sru:~# cat /etc/NetworkManager/system-connections/aaaUPTOWN [connection] id=aaaUPTOWN uuid=491fa5c8-68ef-0000-1111-dca422f5c262 type=wifi [wifi] ssid=aaaUPTOWN mode=infrastructure mac-address=E0:9D:31:09:84:54 [ipv6] method=auto [ipv4] method=auto root@mm-nm-sru:~# sudo chmod 600 /etc/NetworkManager/system-connections/*UPTOWN* # Valid connection profiles are loaded into the old NM version as keyfiles in /etc/NetworkManager/ root@mm-nm-sru:~# ls -la /etc/NetworkManager/system-connections/ total 16 drwxr-xr-x 2 root root 4096 Oct 18 13:11 . drwxr-xr-x 7 root root 4096 Oct 18 13:11 .. -rw------- 1 root root 199 Oct 18 13:11 UPTOWN.guests -rw------- 1 root root 191 Oct 18 13:11 aaaUPTOWN root@mm-nm-sru:~# sudo nmcli con reload root@mm-nm-sru:~# nmcli c NAME UUID TYPE DEVICE aaaUPTOWN 491fa5c8-68ef-0000-1111-dca422f5c262 wifi -- # Upgrade to SRU version of NetworkManager root@mm-nm-sru:~# vim /etc/apt/sources.list # enable -proposed root@mm-nm-sru:~# apt update && apt install -t mantic-proposed network-manager Hit:1 http://archive.ubuntu.com/ubuntu mantic InRelease Hit:2 http://archive.ubuntu.com/ubuntu mantic-updates InRelease Get:3 http://archive.ubuntu.com/ubuntu mantic-proposed InRelease [256 kB] Hit:4 http://security.ubuntu.com/ubuntu mantic-security InRelease Hit:5 http://archive.ubuntu.com/ubuntu mantic-backports InRelease Get:6 http://archive.ubuntu.com/ubuntu mantic-proposed/main amd64 Packages [9428 B] Get:7 http://archive.ubuntu.com/ubuntu mantic-proposed/main Translation-en [3480 B] Get:8 http://archive.ubuntu.com/ubuntu mantic-proposed/main amd64 DEP-11 Metadata [7604 B] Get:9 http://archive.ubuntu.com/ubuntu mantic-proposed/main amd64 c-n-f Metadata [292 B] Get:10 http://archive.ubuntu.com/ubuntu mantic-proposed/restricted amd64 c-n-f Metadata [116 B] Fetched 277 kB in 1s (532 kB/s) Reading package lists... Done Building dependency tree... Done Reading state information... Done 3 packages can be upgraded. Run 'apt list --upgradable' to see them. Reading package lists... Done Building dependency tree... Done Reading state information... Done The following additional packages will be installed: libnm0 Suggested packages: avahi-autoipd libteam-utils The following packages will be upgraded: libnm0 network-manager 2 upgraded, 0 newly installed, 0 to remove and 5 not upgraded. Need to get 2809 kB of archives. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] Get:1 http://archive.ubuntu.com/ubuntu mantic-proposed/main amd64 network-manager amd64 1.44.2-1ubuntu1.1 [2331 kB] Get:2 http://archive.ubuntu.com/ubuntu mantic-proposed/main amd64 libnm0 amd64 1.44.2-1ubuntu1.1 [478 kB] Fetched 2809 kB in 1s (2511 kB/s) (Reading database ... 33906 files and directories currently installed.) Preparing to unpack .../network-manager_1.44.2-1ubuntu1.1_amd64.deb ... Unpacking network-manager (1.44.2-1ubuntu1.1) over (1.44.2-1ubuntu1) ... Preparing to unpack .../libnm0_1.44.2-1ubuntu1.1_amd64.deb ... Unpacking libnm0:amd64 (1.44.2-1ubuntu1.1) over (1.44.2-1ubuntu1) ... Setting up libnm0:amd64 (1.44.2-1ubuntu1.1) ... ######################### # Here is the relevant NetworkManager Netplan migration. # The invalid UPTOWN.guests file is skipped # The valid aaaUPTOWN profile is migrated ######################### Setting up network-manager (1.44.2-1ubuntu1.1) ... Error: 491fa5c8-68ef-4140-8679-dca422f5c262 - no such connection profile. SKIP: UPTOWN.guests (491fa5c8-68ef-4140-8679-dca422f5c262) unknown to NetworkManager. Migrating aaaUPTOWN (491fa5c8-68ef-0000-1111-dca422f5c262) to /etc/netplan Processing triggers for dbus (1.14.10-1ubuntu1) ... Processing triggers for libc-bin (2.38-1ubuntu6) ... Processing triggers for man-db (2.11.2-3) ... Scanning processes... No services need to be restarted. No containers need to be restarted. No user sessions are running outdated binaries. No VM guests are running outdated hypervisor (qemu) binaries on this host. root@mm-nm-sru:~# echo $? 0 # Verifying the final state root@mm-nm-sru:~# sudo grep -RH UPTOWN /etc/netplan/ /etc/netplan/90-NM-491fa5c8-68ef-0000-1111-dca422f5c262.yaml: "aaaUPTOWN": /etc/netplan/90-NM-491fa5c8-68ef-0000-1111-dca422f5c262.yaml: name: "aaaUPTOWN" /etc/netplan/90-NM-491fa5c8-68ef-0000-1111-dca422f5c262.yaml: name: "aaaUPTOWN" root@mm-nm-sru:~# ls -la /etc/NetworkManager/system-connections/ total 12 drwxr-xr-x 2 root root 4096 Oct 18 13:13 . drwxr-xr-x 7 root root 4096 Oct 18 13:13 .. -rw------- 1 root root 199 Oct 18 13:11 UPTOWN.guests root@mm-nm-sru:~# dpkg -l network-manager Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-===============-=================-============-========================================================= ii network-manager 1.44.2-1ubuntu1.1 amd64 network management framework (daemon and userspace tools) root@mm-nm-sru:~# ll /etc/netplan/ total 16 drwxr-xr-x 2 root root 4096 Oct 18 13:13 ./ drwxr-xr-x 103 root root 4096 Oct 18 13:13 ../ -rw------- 1 root root 389 Oct 18 13:10 50-cloud-init.yaml -rw------- 1 root root 540 Oct 18 13:13 90-NM-491fa5c8-68ef-0000-1111-dca422f5c262.yaml