This happened after update. I'm running it on ElementaryOS 6.1.

Here's the output after I run the command flatpak run com.viber.Viber:

QIBusPlatformInputContext: invalid portal bus.
Qt: Session management error: None of the authentication protocols specified are supported
QApplication: invalid style override 'adwaita' passed, ignoring it.
Available styles: Windows, Fusion
sh: line 1: xdg-mime: command not found

GLImplementation: desktop
Surface Type: OpenGL
Surface Profile: NoProfile
Surface Version: 3.1
Using Default SG Backend: yes
Using Software Dynamic GL: no
Using Angle: no

Init Parameters:

    application-name ViberPC
    autoplay-policy no-user-gesture-required
    browser-subprocess-path /app/extra/viber/libexec/QtWebEngineProcess
    disable-features DnsOverHttpsUpgrade,ConsolidatedMovementXY,InstalledApp,BackgroundFetch,WebOTP,WebPayments,WebUSB,PictureInPicture,AudioServiceOutOfProcess
    enable-features NetworkServiceInProcess,TracingServiceInProcess,NetworkServiceInProcess
    use-gl desktop

QQmlApplicationEngine failed to load component
qrc:/Resources/QML/MainWindow.qml: module "adwaita" is not installed
qt.core.qobject.connect: QObject::connect(QWindow, ApplicationEngine): invalid nullptr parameter

Also tried to downgrade to older flatpak versions, but there still are some issues, some are different from

1 Answer 1


It seemed there is a bug in QT: https://bugreports.qt.io/browse/QTBUG-99889. To launch, try the command:

env QT_STYLE_OVERRIDE= flatpak run com.viber.Viber

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