NetworManager crashes when modifing connection (ipv4.ignore-auto-routes yes)

[RO1]

When trying to connect with forticlient to an SSL-VPN, the connection will fail with "Config DNS failed"
Then i was searching in logs of forticlient and found:

20241127 07:07:55.291 TZ=+0100 [sslvpn:EROR] nmtools:255 Command to set ipv4.ignore-auto-routes returned with status 256.
20241127 07:07:55.291 TZ=+0100 [sslvpn:EROR] nmtools:1060 Failed to modify connection mpqemubr0 property ipv4.ignore-auto-routes
20241127 07:07:55.291 TZ=+0100 [sslvpn:EROR] dns:1007 Failed to finish Network Manager configuration
20241127 07:07:55.291 TZ=+0100 [sslvpn:EROR] vpn_connection:2071 Config DNS failed

Next i was searching what this means.
So i tried to reproduce this - without forticlient.
And i can reproduce:

# find UUID
nmcli con show | grep mpqemubr0
   mpqemubr0 afb3b269-839b-4ce1-9078-e8ad740b784e bridge mpqemubr0

# check current setting
nmcli con show afb3b269-839b-4ce1-9078-e8ad740b784e | grep ipv4.ignore-auto-routes
   ipv4.ignore-auto-routes: no

# change setting
nmcli con modify afb3b269-839b-4ce1-9078-e8ad740b784e ipv4.ignore-auto-routes yes
   Error: Failed to modify connection 'mpqemubr0': Message recipient disconnected from message bus without replying

set logging for NetworkManager to trace for all domains i see this:

Nov 29 09:57:10 myhost NetworkManager[98631]: <trace> [1732870630.7383] auth: call[4]: completed: authorized=1, challenge=0
Nov 29 09:57:10 myhost NetworkManager[98631]: <debug> [1732870630.7385] audit: socket created
Nov 29 09:57:10 myhost NetworkManager[98631]: <debug> [1732870630.7385] create NMAuditManager singleton (7794fbd712da6ac4)
Nov 29 09:57:10 myhost NetworkManager[98631]: <trace> [1732870630.7386] settings: add-connection: failed to add afb3b269-839b-4ce1-9078-e8ad740b784e/'mpqemubr0': settings plugin does not support adding connections
Nov 29 09:57:10 myhost generate[99193]: nm-device: NM-2a2a93e2-e395-4291-8c71-b4c90d5b8211: the renderer for nm-devices must be NetworkManager, it will be used instead of the defined one.
Nov 29 09:57:10 myhost generate[99193]: nm-device: NM-649ca4e6-0058-4ca4-8b13-b2b386326d64: the renderer for nm-devices must be NetworkManager, it will be used instead of the defined one.
Nov 29 09:57:10 myhost generate[99193]: nm-device: NM-9fe9febf-03de-4534-b27d-e4f309760a10: the renderer for nm-devices must be NetworkManager, it will be used instead of the defined one.
Nov 29 09:57:11 myhost NetworkManager[98631]: <trace> [1732870631.8468] keyfile: commit: afb3b269-839b-4ce1-9078-e8ad740b784e (mpqemubr0) added as "/run/NetworkManager/system-connections/netplan-mpqemubr0.nmconnection"
Nov 29 09:57:11 myhost NetworkManager[98631]: **
Nov 29 09:57:11 myhost NetworkManager[98631]: nm:ERROR:src/core/settings/nm-settings-utils.c:103:<unknown-fcn>: assertion failed: (<dropped>)
Nov 29 09:57:11 myhost NetworkManager[98631]: Bail out! nm:ERROR:src/core/settings/nm-settings-utils.c:103:<unknown-fcn>: assertion failed: (<dropped>)
Nov 29 09:57:12 myhost systemd[1]: NetworkManager.service: Main process exited, code=dumped, status=6/ABRT
Nov 29 09:57:12 myhost systemd[1]: NetworkManager.service: Failed with result 'core-dump'.
Nov 29 09:57:12 myhost systemd[1]: NetworkManager.service: Scheduled restart job, restart counter is at 2.
Nov 29 09:57:12 myhost systemd[1]: Starting NetworkManager.service - Network Manager...

The interface mpqemubr0 is coming from multipass 1.14.1

1) The release of Ubuntu you are using, via 'lsb_release -rd' or System -> About Ubuntu

Description: Ubuntu 24.04.1 LTS
Release: 24.04

2) The version of the package you are using, via 'apt-cache policy pkgname' or by checking in Software Center

network-manager: 1.46.0-1ubuntu2
nmcli tool : 1.46.0

3) What you expected to happen

- nmcli-action is working
- NetworkManager is not crashing/dumping with "NetworkManager.service: Main process exited, code=dumped, status=6/ABRT" and then restarting
- VPN connection is working/useable

4) What happened instead

- wanted nmcli action is not working
- VPN is not working

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: network-manager 1.46.0-1ubuntu2
ProcVersionSignature: Ubuntu 6.8.0-49.49-generic 6.8.12
Uname: Linux 6.8.0-49-generic x86_64
NonfreeKernelModules: zfs
ApportVersion: 2.28.1-0ubuntu3.1
Architecture: amd64
CasperMD5CheckResult: pass
Date: Fri Nov 29 14:37:40 2024
ExecutablePath: /usr/sbin/NetworkManager
InstallationDate: Installed on 2024-10-13 (47 days ago)
InstallationMedia: Ubuntu 24.04.1 LTS "Noble Numbat" - Release amd64 (20240827.1)
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
ProcEnviron:
 LANG=en_US.UTF-8
 PATH=(custom, no user)
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-nm:
 RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
 running 1.46.0 connected started full enabled missing enabled missing enabled

[Danilo Egea Gondolfo (danilogondolfo)]

Hi,

If you run 'sudo netplan generate' in your terminal, do you see any errors?

[RO1 (ro77)]

Hi,
just some Warnings:

sudo netplan generate

** (generate:300704): WARNING **: 17:18:01.771: nm-device: NM-2a2a93e2-e395-4291-8c71-b4c90d5b8211: the renderer for nm-devices must be NetworkManager, it will be used instead of the defined one.

** (generate:300704): WARNING **: 17:18:01.771: nm-device: NM-649ca4e6-0058-4ca4-8b13-b2b386326d64: the renderer for nm-devices must be NetworkManager, it will be used instead of the defined one.

** (generate:300704): WARNING **: 17:18:01.772: nm-device: NM-9fe9febf-03de-4534-b27d-e4f309760a10: the renderer for nm-devices must be NetworkManager, it will be used instead of the defined one.

[Peter Durovic (naimad-the-one)]

I have the same problem, and the trigger was updating FortiClient from version 7.2.5 to 7.2.6.

sudo netplan generate -> show warning

I fix it with move configuration from NetPlan to NetworkManager but I'm still unable to connect to VPN.