Problem: kwin5-5.1.0-1.1.x86_64 requires libkdecorations.so.5()(64bit), but this requirement cannot be provided
  uninstallable providers: libkdecorations5-5.1.0-1.1.x86_64[download.opensuse.org-oss]
                   libkdecorations5-5.1.1-4.5.x86_64[repo-update]
 Solution 1: deinstallation of libkdecorations2-5-5.2.0-2.1.x86_64
 Solution 2: keep obsolete plasma5-session-5.1.95-12.1.noarch
 Solution 3: install kwin5-5.1.1-4.5.i586 despite the inferior architecture
 Solution 4: break kwin5-5.1.0-1.1.x86_64 by ignoring some of its dependencies