Choose a maintained package
KDE’s application page links its supported application-store route and notes that a distribution package manager can also be used. Start there, and record the package source and version. Do not assume a nightly build, a distribution package and an unrelated download mirror contain the same release.
If you already have mpv installed, keep that as a separate application record. Haruna uses libmpv but still has its own interface, dependencies and settings. An issue should name Haruna and the package source so a maintainer can distinguish it from the command-line player.
Establish ordinary file playback first
Open a local file you are entitled to use. Confirm that the window renders video, sound reaches the intended output and pause or seeking works. A file that plays in a second application supplies a useful comparison, but it is not proof that Haruna’s installation or display integration is identical.
Use a short familiar clip and leave custom commands out of this first run. If the entire player window is unresponsive, report that separately from a picture that freezes while the controls remain usable. Those observations point to different layers of the application.
Configure controls for the actual viewing position
KDE documents configurable keyboard shortcuts and mouse buttons, along with a playlist that can overlay the video. Check the controls you need from your normal seat before committing to a long session. A computer player that works well at a desk may need a different input arrangement beside a television.
Keep a reliable route back from full screen and verify that the playlist can be dismissed without changing the selected media. If you remap shortcuts, write down the change. This avoids treating a deliberately changed key as an application failure later.
Treat online playback as a distinct test
KDE documents online-video support, but that is not a promise to accept every account, portal or protected streaming service. Use only a permitted input that the application understands. A remote item failing while local video works narrows the question to source access, supported formats or online integration.
For a useful support report, include the distribution, display-session type, package version and whether local playback succeeds. Remove passwords and private query strings from any URL. Record the visible error verbatim and the input type, so troubleshooting does not start by guessing which service interface you used.