In the desktop file `org.kde.kdeconnect_open.desktop`, the `MimeType` is `*/*`. `update-desktop-database` is a tool provided in `desktop-file-utils` that > updates the database containing a cache of MIME types handled by desktop files When running `update-desktop-database`, it throws an error saying that > "*/*" is an invalid MIME type ("*" is an unregistered media type) This is reported in [Clear Linux](https://github.com/clearlinux/distribution/issues/1906) and [Arch Linux](https://bugs.archlinux.org/task/65865) STEPS TO REPRODUCE 1. Run `update-desktop-database` OBSERVED RESULT > "*/*" is an invalid MIME type ("*" is an unregistered media type)
Is that probably what the "all/allfiles" type is for?
I can reproduce this in v1.4, might be present in later versions too. */* is not a valid mime type. If I assume this mime type is supposed to include all files, the valid mime type for that is application/octet-stream. Modifying /usr/share/applications/org.kde.kdeconnect_open.desktop to reflect the same fixes the issue.
there's multiple validation errors with this .desktop file, MimeType is one: $ desktop-file-validate kdeconnect-kde-20.04.0/data/org.kde.kdeconnect_open.desktop | grep error: kdeconnect-kde-20.04.0/data/org.kde.kdeconnect_open.desktop: error: (will be fatal in the future): value "*/*;" for key "MimeType" in group "Desktop Entry" contains value "*/*" which is an invalid MIME type: "*" is an unregistered media type kdeconnect-kde-20.04.0/data/org.kde.kdeconnect_open.desktop: error: key "MimeType" is present in group "Desktop Entry", but the type is "Service" while this key is only valid for type "Application" kdeconnect-kde-20.04.0/data/org.kde.kdeconnect_open.desktop: error: key "Exec" is present in group "Desktop Entry", but the type is "Service" while this key is only valid for type "Application" kdeconnect-kde-20.04.0/data/org.kde.kdeconnect_open.desktop: error: key "Terminal" is present in group "Desktop Entry", but the type is "Service" while this key is only valid for type "Application" kdeconnect-kde-20.04.0/data/org.kde.kdeconnect_open.desktop: error: key "Categories" is present in group "Desktop Entry", but the type is "Service" while this key is only valid for type "Application"
You can fix this by changing */* to application/octet-stream as suggested by Saikat Patra. There are patches to this end for a number of distributions all over the internet, like here: https://github.com/void-linux/void-packages/commit/17060bfa012b12896d3d7ec502caa154af6135b4, but it's an upstream issue.
Fixed per this merge request https://invent.kde.org/network/kdeconnect-kde/-/merge_requests/327 and commit: https://invent.kde.org/network/kdeconnect-kde/-/commit/f1ce22124ce7dd630b8e909b4c50f90f035166d5