You can check if a PO file is valid with the following command:

        msgfmt -c -o /dev/null <po file>
      

The following errors were found in 389-ds-base 's PO files:

gettext: src/cockpit/389-console/po/ja.po:6863: duplicate message definition...
src/cockpit/389-console/po/ja.po:6825: ...this is the location of the first definition
src/cockpit/389-console/po/ja.po:7319: duplicate message definition...
src/cockpit/389-console/po/ja.po:5516: ...this is the location of the first definition
msgfmt: found 2 fatal errors
      

Please ask the translator (identified by the Last-Translator field in the PO file), the language team (identified by the Language-Team field) or debian-i18n for a fix.