import of wiregard vpn definition file flags mtu parameter as invalid

[ArturRuta]

Environment:

Opsys: Fedora workstation version 44
kernel: Linux 7.1.4-202.fc44.x86_64
cosmic-settings-1.3.0-1.fc44.x86_64
cosmic-comp-1.3.0-1.fc44.x86_64

Symptoms:

In Network and Wireless Settings --> VPN: When importing a valid wireguard configuration file I'm getting:

org.freedesktop.NetworkManager.Settings.Connection.InvalidProperty: ip4.mtu: unknown property

The file does contains an MTU = 1412 parameter under the [Interface] section but this is completely valid

Complementary info:

The problem is new. This import operation with the same file was successful in earlier versions of the settings as recently ans june 2026, therefore i suspect of some regression.

Layout of the file producing the failure (actual keys and addresses changed for privacy)

[Interface]
PrivateKey = TheRealPrivateKeyGoesHere
Address = 192.168.1.10/32
DNS = 192.168.1.1
MTU = 1412

[Peer]
PublicKey = TheRealPublicKeyGoesHere
Endpoint = myserver.mydomain.net:50000
AllowedIPs = 0.0.0.0/0,::/0

Bypass

Importing the configuration directly using nmcli as shown below works ok and the vpn can then be activated/deactivated from cosmic with no issues

nmcli connection import type wireguard file /path/to/my/file.conf

Last remarks

The problem persists if i retry the file import.
Can reproduce at will
If you need any additional info just let me know.
Best regards and thank you for such a good desktop environment. Really enjoying it.

[KodeBarista]

Were you able to import any other WireGuard configurations at all? If so, were you able to access the internet?
I have several WG configs, two of which were denied during import. I tried the ones that were imported, but the internet was inaccessible.

I'm on Fedora 44 COSMIC

Edit: After discovering this issue after update I quickly did a re-install & imported configs before update & now everything works.

[ArturRuta]

Hi just have one wireguard server to access so i cannot try multiple configurations.
Only thing I can say is tant once the configuration was imported using nmcli as shown avobe I was able to connect and disconnect successfully using the cosmic gui with no issues.
Since you explain you succeeded in importing before the update then it matches what i said above as i was able to do the import with no issues in earlier versions of cosmic desktop but not in current one, hence the suspiction of some regression involved.

[cachebag]

This has been fixed in freedesktop-rs/nmrs#505

I am cutting a release soon that will close this issue.