SUMMARY
Haruna Media Player does not automatically play .mp4 files when directly opened from the file manager, though the application does launch. The files can be played without issue when opened from within an instance of Haruna Media Player.

STEPS TO REPRODUCE
1. Set Haruna Media Player as the default player for .mp4 files.
2. Navigate to an .mp4 file using a file manager.
3. Double click the .mp4 file to open it.

OBSERVED RESULT
Haruna Media Player opens, but the video does not start playing automatically. It appears that the file isn't loaded into Haruna's playlist.

EXPECTED RESULT
When an .mp4 file is opened, Haruna Media Player should launch and automatically start playing the selected video.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux 6.2.13-arch1-1
(available in About System)
KDE Plasma Version: 5.27.5
KDE Frameworks Version: 5.105.0
Qt Version: 5.15.9

ADDITIONAL INFORMATION
When attempting to open the .mp4 file from the terminal using the haruna /path/to/video.mp4 command, several QML-related warnings and errors were displayed, including deprecated usages and binding loop issues. However, these do not seem to directly prevent the file from being opened and played.

unknown() : qrc:/qml/main.qml:180:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
unknown() : qrc:/qml/Actions.qml:39:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
unknown() : qrc:/qml/HProgressBar.qml:227:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
unknown() : qrc:/qml/PlayList.qml:327:5: QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
unknown() : file:///usr/lib/qt/qml/org/kde/kirigami.2/ScrollablePage.qml:200:9: QML MouseArea: Binding loop detected for property "width"
unknown() : file:///usr/lib/qt/qml/QtQuick/Controls.2/org.kde.desktop/Menu.qml:33:15: QML MenuItem: Binding loop detected for property "implicitWidth"
unknown() : file:///usr/lib/qt/qml/QtQuick/Controls.2/org.kde.desktop/Menu.qml:33:15: QML MenuItem: Binding loop detected for property "implicitWidth"
unknown() : file:///usr/lib/qt/qml/QtQuick/Controls.2/org.kde.desktop/Menu.qml:33:15: QML MenuItem: Binding loop detected for property "implicitWidth"
unknown() : file:///usr/lib/qt/qml/QtQuick/Controls.2/org.kde.desktop/Menu.qml:33:15: QML MenuItem: Binding loop detected for property "implicitWidth"
unknown() : file:///usr/lib/qt/qml/QtQuick/Controls.2/org.kde.desktop/Menu.qml:33:15: QML MenuItem: Binding loop detected for property "implicitWidth"
unknown() : file:///usr/lib/qt/qml/QtQuick/Controls.2/org.kde.desktop/Menu.qml:33:15: QML MenuItem: Binding loop detected for property "implicitWidth"