MuseScore crashes when changing theme

[KelvinNovais]

Issue type

Crash or freeze

Bug description

The app crashes whenever the system theme is changed.

Additionally, even if you set (Edit > Preferences > Appearance > "Follow system theme") to false, Musescore crashes anyway.

Steps to reproduce

1. Open the app (it doesn't care which page you are)
2. Change the system theme
3. Wait some time and see it crashing

Screenshots/Screen recordings

Screencast.from.2024-04-05.00-23-26.webm

MuseScore Version

4.2.1 (Flatpak)

Regression

I don't know

Operating system

Fedora 39

Additional context

Terminal output:

(...)

00:36:21.671 | WARN  | main_thread     | Qt              | Could not find color scheme  ""
00:36:21.674 | WARN  | main_thread     | Qt              | Could not find color scheme  ""
00:36:21.704 | WARN  | main_thread     | Qt              | Could not find color scheme  ""
00:36:21.706 | WARN  | main_thread     | Qt              | Could not find color scheme  ""

[Jojo-Schmitz]

Does the AppImage crash too? Only that is supported here...

[zacjansheski]

I haven't reproduced with appimage on Ubuntu

[KelvinNovais]

AppImage works perfectly on Fedora.

Maybe the problem is caused by KDE flatpak runtime: it may mask the theme keyword when it changes, or something else... I'm not sure...

But, if the theme wasn't found, isn't it possible to keep the current configuration? Of course this isn't the best solution, however avoids crashing the app.

[zacjansheski]

I am closing this as we are only actively working on supporting AppImage