Created attachment 103225 [details]
Screenshot showing missing task switcher icons in KDE 5.

I'm using current KDE Plasma, Frameworks and Applications from the KDE Neon project together with the Oxygen Icon theme which I prefer a lot over the Breeze icon theme.

However since switching to KDE Neon (and, with that, somewhat more recent versions of the KDE 5 components), I'm missing the kMail and Konsole icons in the task switcher, while the application's window decorations still show the appropriate application icon.

As far as I can see, at least in source Oxygen provides a scalable kmail2 SVG icon and several sizes of bitmap icons.

I'm not sure if this is a bug in Oxygen Icons or KDE Neon packaging, or if it is not even supposed to work. (However, shouldn't KDE fall back to some kind of default icon if Oxygen for some reason does not provide the appropriate ones?)

My Oxygen Icon set is currently at package version 5:5.29.0+p16.04+git20170105.0647-0.

Plasma desktop is at version 4:5.8.5+p16.04+git20170104.0343-0.

kMail is at version 4:16.12.0+p16.04+git20161228.0807-0.

Konsole is at version 4:16.12.0+p16.04+git20161220.0222-0.