SUMMARY *** The message you see in the logs indicates that there is an issue with casting a Python object of type NoneType to a C++ object of type std::string. This suggests that there is a problem with the way the Python and C++ code interacts. *** STEPS TO REPRODUCE craudio@acer-debian:~$ flatpak run org.kde.audiotube QSocketNotifier: Can only be used with threads started with QThread futuresql: Migrations finished futuresql: Running "select distinct (search_query) from searches order by search_id desc" futuresql: Running "select * from favourites natural join songs order by favourites.rowid desc" futuresql: Running "select * from played_songs natural join songs" futuresql: Running "select * from played_songs natural join songs order by plays desc limit 10" Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") futuresql: Running "select * from playlists" Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") futuresql: Running "select * from playlists" futuresql: Running "select * from playlists" qrc:/main.qml:98:17: Unable to assign null to double qrc:/MinimizedPlayerControls.qml:246:13: Unable to assign bool to int qrc:/dialogs/PlaylistDialog.qml:42:9: QML ImportPlaylistDialog: Binding loop detected for property "implicitHeight" qrc:/dialogs/PlaylistDialog.qml:38:9: QML AddPlaylistDialog: Binding loop detected for property "implicitHeight" qrc:/LibraryPage.qml:441:9: QML RenamePlaylistDialog: Binding loop detected for property "implicitHeight" qrc:/dialogs/PlaylistDialog.qml:42:9: QML ImportPlaylistDialog: Binding loop detected for property "implicitHeight" qrc:/dialogs/PlaylistDialog.qml:38:9: QML AddPlaylistDialog: Binding loop detected for property "implicitHeight" qrc:/SearchWithDropdown.qml:241:9: QML NumberAnimation: Binding loop detected for property "from" qrc:/main.qml:98:17: Unable to assign null to double qrc:/MinimizedPlayerControls.qml:246:13: Unable to assign bool to int qrc:/MinimizedPlayerControls.qml:142:9: Unable to assign null to QQuickAnchorLine futuresql: Running "insert into searches (search_query) values (?)" Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") futuresql: Running "select * from playlists" futuresql: Running "insert into searches (search_query) values (?)" Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") futuresql: Running "select * from playlists" Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") Cannot initialize model with data QJsonObject(). missing: QJsonValue(string, "urls") futuresql: Running "select * from playlists" qrc:/components/DoubleActionButton.qml:131:9: Unable to assign [undefined] to int Unable to cast Python instance of type <class 'NoneType'> to C++ type 'std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > OBSERVED RESULT Here's a breakdown of the error message: Unable to cast Python instance: This phrase indicates that the system tried to convert a Python object into another data type but failed. of type <class 'NoneType'>: This part of the message tells us what type of Python object was being converted. In this case, it's a NoneType, which means the object has no value or doesn't exist. to C++ type 'std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >': This part of the message shows the type of object that the system tried to convert the Python object to. It's a C++ string class called std::string. The error occurs because the Python NoneType object cannot be directly converted to a C++ std::string object. The two types are not compatible, so the conversion fails. This issue might happen when your application tries to use a Python module or function that returns None (or no value) instead of a string, while the C++ side expects a string as input. To fix this, you need to check the interface between Python and C++ and ensure that the types match correctly. You may also want to verify that the Python module or function you're using behaves as expected and returns the correct type of data. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Debian testing KDE Plasma Version: 5.27.9 KDE Frameworks Version: 5.107.0 Qt Version: 5.15.10 Kernel: 6.5.0-5-amd64 (64bit) Wayland ADDITIONAL INFORMATION The same occur in Gnome 44.7