As I see the problem is in Ubuntu version of the package plasma-workspace: http://anonscm.debian.org/cgit/pkg-kde/plasma/plasma-workspace.git/tree/debian/control?h=kubuntu_stable
Probably it should be sync with Debian version of the package. In particular: http://anonscm.debian.org/cgit/pkg-kde/plasma/plasma-workspace.git/tree/debian/control#n162
... Package: plasma-workspace ... Breaks: plasma-systray-legacy, ... Replaces: plasma-systray-legacy, ...
xembedsniproxy module was included into plasma-workspace since release 5.5.0, so a separate package plasma-systray-legacy is not required anymore and it might be freely removed from Ubuntu >= 16.04.
As I see the problem is in Ubuntu version of the package plasma-workspace: anonscm. debian. org/cgit/ pkg-kde/ plasma/ plasma- workspace. git/tree/ debian/ control? h=kubuntu_ stable
http://
Probably it should be sync with Debian version of the package. In particular: anonscm. debian. org/cgit/ pkg-kde/ plasma/ plasma- workspace. git/tree/ debian/ control# n162
http://
... systray- legacy, systray- legacy,
Package: plasma-workspace
...
Breaks: plasma-
...
Replaces: plasma-
...
xembedsniproxy module was included into plasma-workspace since release 5.5.0, so a separate package plasma- systray- legacy is not required anymore and it might be freely removed from Ubuntu >= 16.04.