Comment # 3 on bug 1027925 from Wolfgang Bauer

It's likely related to those bug#1011132 and bug#1016803, I'd say:

In short:
- libqt5-qttranslations is not installed by default
- bundle-lang-kde-xxx is "broken", it misses some translations (actually caused
by how the %find_lang rpm macro works)

Installing libqt5-qttranslations and libKF5WidgetsAddons-lang (and maybe other
-lang packages) manually should fix it.

@P. Otato: Can you confirm that?