Invalid desktop files in .local/share/applications

[Martin-Buchholz]

desktop-file-validate complains about orangepi desktop files:

$ desktop-file-validate .local/share/applications/{orangepi*,xfce4-about*}.desktop
.local/share/applications/orangepi-support.desktop: hint: value "GTK;GNOME;X-Xfce-Toplevel;" for key "Categories" in group "Desktop Entry" does not contain a registered main category; application might only show up in a "catch-all" section of the application menu
.local/share/applications/orangepi-support.desktop: error: key "StartupNotify" is present in group "Desktop Entry", but the type is "Link" while this key is only valid for type "Application"
.local/share/applications/orangepi-support.desktop: error: key "Terminal" is present in group "Desktop Entry", but the type is "Link" while this key is only valid for type "Application"
.local/share/applications/orangepi-support.desktop: error: key "Categories" is present in group "Desktop Entry", but the type is "Link" while this key is only valid for type "Application"
.local/share/applications/xfce4-about.desktop: error: file is empty