Hi,
After recent update of KDE Plasma 5 in Debian Sid,
latest plasma-desktop-data break and replace all kde-l10n-* files and make all
translations incomplete.
I use this little workaround for waiting new kde-l10n-* packages:
Make /usr/share/locale/fr/LC_MESSAGES/ backup.
I downloaded old kde-l10n-fr_4.14.0-3_all package, extract and copy all *.mo
files to /usr/share/locale/fr/LC_MESSAGES/
kde-l10n-fr_4.14.0-3_all/usr/share/locale/fr/LC_MESSAGES$ sudo cp *.mo
/usr/share/locale/fr/LC_MESSAGES/
Best wishes,
Laurent