App crashed when openning the file browser

Qt6 app is crashing when trying to open file browser within the app.

(stellarium:21470): GLib-GIO-ERROR **: 15:12:33.718: No GSettings schemas are installed on the system Trace/breakpoint trap (core dumped)

yaml file : https://github.com/t4saha/stellarium-snap/blob/master/snap/snapcraft.yaml

Same for me (PyQt6 app):

(python:53487): GLib-GIO-ERROR **: 19:40:28.924: No GSettings schemas are installed on the system
Trace/breakpoint trap (core dumped)

Solved my case by updating qt helper definitions (added libglib2.0-0 in stage-packages and glib-compile-schemas in override-prime:

  desktop-qt5:
    source: https://github.com/ubuntu/snapcraft-desktop-helpers.git
    source-subdir: qt
    plugin: make
    make-parameters: ["FLAVOR=qt5"]
    build-packages:
      - qtbase5-dev
      - dpkg-dev
    stage-packages:
      - libxkbcommon0
      - fonts-ubuntu
      - dmz-cursor-theme
      - light-themes
      - adwaita-icon-theme
      - gnome-themes-standard
      - shared-mime-info
      - libqt5gui5
      - libgdk-pixbuf2.0-0
      - libqt5svg5 # for loading icon themes which are svg
      - locales-all
      - libglib2.0-0
    override-prime: |
      craftctl default
      glib-compile-schemas usr/share/glib-2.0/schemas