[Post-Install] Webcam completely broken in Wayland on 26.04 — org.freedesktop.portal.Camera entirely missing from all packages

[scallaway]

System: Kubuntu 26.04 (Resolute), KDE Plasma (Wayland), kernel 7.0.0-22-generic, Logitech BRIO 4K (Logi 4K Stream Edition)

Problem: After a recent system update, the webcam shows a black screen in all Wayland apps — Slack, Microsoft Edge, GNOME Snapshot. The camera LED turns on, indicating the device is being opened, but no frames are received.

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Root cause

The org.freedesktop.portal.Camera interface is completely absent from Ubuntu 26.04's packages. This interface is required for any Wayland app to receive camera frames — without it, apps open the device but get nothing back. Confirmed with:

gdbus call --session \
--dest org.freedesktop.portal.Desktop \
--object-path /org/freedesktop/portal/desktop \
--method org.freedesktop.portal.Camera.IsCameraPresent

Error: GDBus.Error:org.freedesktop.DBus.Error.UnknownMethod: No such method "IsCameraPresent"​

Further investigation confirmed the interface is missing across all four installed portal packages:

• org.freedesktop.portal.Camera.xml not shipped by xdg-desktop-portal — dpkg -L xdg-desktop-portal | grep xml returns nothing
• grep -r "Camera" /usr/share/xdg-desktop-portal/portals/ returns nothing — Camera absent from kde.portal, gnome.portal, and gtk.portal
• strings /usr/lib/x86_64-linux-gnu/libexec/xdg-desktop-portal-kde | grep -i camera — empty
• strings /usr/libexec/xdg-desktop-portal-gnome | grep -i camera — empty

All four packages (xdg-desktop-portal 1.21.1, xdg-desktop-portal-kde 6.6.4, xdg-desktop-portal-gnome 50.0, xdg-desktop-portal-gtk 1.15.3) have zero Camera support.

The camera hardware, uvcvideo driver, and PipeWire are all working correctly — this is purely a portal packaging failure.

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Additional issues found during debugging

• wireplumber 0.5.13 crashes with SIGABRT on manual restart (GObject assertion failure in libwireplumber-module-lua-scripting.so)
• state-stream.lua:359 Lua type error (attempt to compare number with table in buildDefaultChannelVolumes) floods the log on every start
• libcamera and v4l2 SPA plugins both claim the BRIO simultaneously, causing MJPEG frame corruption in direct v4l2 pipelines (workaround: disable libcamera monitor in WirePlumber)

[Schwarzer Kater]

Welcome.

This sounds like a general problem in *Ubuntu 26.04, doesn't it? Correct me if I'm wrong.

Have you already tested this with Ubuntu 26.04 Desktop (GNOME)?
Should the problem persists there as well, Canonical itself - or an Ubuntu forum - could be a better place to find solutions, as the Kubuntu forum focuses more on e.g. the KDE Plasma user interface, KDE Applications and other KDE stuff.
Because (to put it very simplyfied) Kubuntu is "just" Ubuntu with KDE Plasma (don't bite my head off, guys… ).

[claydoh]

Are we even using gdbus in KDE? I am thinking not so much. But I imagine other things do.

$ dbus-send --print-reply --dest=org.freedesktop.portal.Desktop /org/freedesktop/portal/desktop org.freedesktop.DBus.Properties.Get string:"org.freedesktop.portal.Camera" string:"IsCameraPresent"

method return time=1780540938.480172 sender=:1.45 -> destination=:1.7226 serial=60683 reply_serial=2
    variant       boolean true

Further investigation confirmed the interface is missing across all four installed portal packages:

• org.freedesktop.portal.Camera.xml not shipped by xdg-desktop-portal — dpkg -L xdg-desktop-portal | grep xml returns nothing

So, is this file actually necessary? My webcam works fine in gnome's Snapshot after getting the portal popup (Emeet 4k, using uvc driver) and I do not have this file. Nor any of the others you also list as missing.

The "missing" file is in the xdg-desktop-portal-dev package, not something normally installed on *buntu and Debian based systems, so I do not believe this is necessary for webcam operation.

I am sure it is a portal problem, but somewhere different.

Are these apps flatpak, snaps, or "native"?

Are you using the stock Plasma 6.5.4, or using the Kubuntu PPA to get 6.6.5 by any chance? Probably a stray rabbit hole for me to go down....

[scallaway]

Thanks so much for getting back to me guys! I should've prefaced my OP with the fact that a lot of the debugging was Claude-driven so apologies if any of it is wildly inaccurate.

Have you already tested this with Ubuntu 26.04 Desktop (GNOME)?
Should the problem persists there as well, Canonical itself - or an Ubuntu forum - could be a better place to find solutions, as the Kubuntu forum focuses more on e.g. the KDE Plasma user interface, KDE Applications and other KDE stuff.

I haven't tried with the Ubuntu desktop yet, but I will get that installed and give it a try. Naturally I've been wanting to try and solve this within KDE (hence me posting here) but that's a reasonable shout.

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Are these apps flatpak, snaps, or "native"?

What do you mean by "native"? I have Slack installed through flatpak. I've completely removed snaps from my system.

Are you using the stock Plasma 6.5.4, or using the Kubuntu PPA to get 6.6.5 by any chance? Probably a stray rabbit hole for me to go down....

"About This System" shows the following information under the "Software" section:
Operating System: Kubuntu 26.04 LTS
KDE Plasma Version: 6.6.4
KDE Frameworks Version: 6.24.0
Qt Version: 6.10.2
Kernel Version: 7.0.0-22-generic (64-bit)
Graphics Platform: Wayland

[claydoh]

What do you mean by "native"?

Native Ubuntu packages, deb files rather than the sandboxed flatpak and snap, or something else.

So the flatpak is not allowing video, but it might be worth checking out other app types, perhaps.

You may need to install kde-config-flatpak of Flatseal to see if Flatpak permissions have changed on these apps.
I don't use any flatpaks that access cameras other than Cameractrls, which is a tool similar to guvcview that I happen to like. It, of course, is working for me, I don't see a way yet to blanket reset permissions for this, assuming that this is the problem.

[scallaway]

Native Ubuntu packages, deb files rather than the sandboxed flatpak and snap, or something else.

Right yep gotcha

You may need to install kde-config-flatpak of Flatseal to see if Flatpak permissions have changed on these apps.

I've checked and I already have that installed.

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I tried Snapshot on ubuntu-desktop but that didn't seem to resolve anything.

[claydoh]

Then you might need to use it to check app permissions to see if anything there fixes things.


It is weird, assuming all Flatpak apps act this way and not just one.
Also checking that any non-Flatpak things (web browsers, etc.) behave in the same manner or not might be good to do.

Even booting to a previous kernel might be useful , if all types of apps do not work.

Apps like guvcview and cameractrls are useful as they offer device settings that can be useful., as well as testing and viewing output.

[scallaway]

I'll go dig out an Ubuntu forum and post in there as well. I have a feeling this is a fundamental 26.04 issue like originally mentioned rather than anything KDE specific (especially since GNOME doesn't fix it)