Hi Jonas, I think I can now confirm the issue is Breeze, then the bug is not in nheko itself.
Launching "env QT_QUICK_CONTROLS_STYLE=Universal nheko" gets to a working nheko instance. A bit weird in the colours, but that's kind-of expected with this kind of workaround. Idea came after finding where that "org.kde.breeze" comes from, as it is not inside nheko source code: it's plasma-mobile to set that variable [1]. A search brought me then to [2] and to the workaround, I guess every non-Breeze style listed in that page should work fine, maybe looking even better than Universal. Now, where is the bug? That environment variable is still set in plasma-mobile on the master (Plasma6/KF6/Qt6) branch [3]. So it's supposed to be there, yet nheko is not finding it. My best hypothesis at the moment, that "org.kde.breeze" QQC (Qt Quick Controls) style should be supplied by binary package qml-module-org-kde-qqc2breezestyle (source qqc2-breeze-style) that is stil at 5.27.11-1 version at the moment in Debian [4]. I see the version of that package in trixie still build-depends on Qt5/KF5, so that's likely conflicting with nheko already depending on Qt6. Please let me know if it's OK for you to keep this bug assigned to nheko until the situation is fixed, so that it's easier for anyone else to find the workaround. Kind regards Marco [1] https://codesearch.debian.net/show?file=plasma-mobile_5.27.10-1%2Fbin%2Fstartplasmamobile.in&line=15 [2] https://doc.qt.io/qt-6/qtquickcontrols-styles.html [3] https://invent.kde.org/plasma/plasma-mobile/-/blob/master/bin/startplasmamobile.in?ref_type=heads#L14 [4] https://packages.debian.org/source/trixie/qqc2-breeze-style
