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 step 's PO files:

gettext: poqm/ar/step_qt.po: qt not a language code
gettext: poqm/be/step_qt.po: qt not a language code
gettext: poqm/bg/step_qt.po: qt not a language code
gettext: poqm/bs/step_qt.po: qt not a language code
gettext: poqm/ca/step_qt.po: qt not a language code
gettext: poqm/ca@valencia/step_qt.po: qt not a language code
gettext: poqm/cs/step_qt.po: qt not a language code
gettext: poqm/da/step_qt.po: qt not a language code
gettext: poqm/de/step_qt.po: qt not a language code
gettext: poqm/el/step_qt.po: qt not a language code
gettext: poqm/en_GB/step_qt.po: qt not a language code
gettext: poqm/eo/step_qt.po: qt not a language code
gettext: poqm/es/step_qt.po: qt not a language code
gettext: poqm/et/step_qt.po: qt not a language code
gettext: poqm/eu/step_qt.po: qt not a language code
gettext: poqm/fi/step_qt.po: qt not a language code
gettext: poqm/fr/step_qt.po: qt not a language code
gettext: poqm/ga/step_qt.po: qt not a language code
gettext: poqm/gl/step_qt.po: qt not a language code
gettext: poqm/gu/step_qt.po: qt not a language code
gettext: poqm/hr/step_qt.po: qt not a language code
gettext: poqm/hu/step_qt.po: qt not a language code
gettext: poqm/ia/step_qt.po: qt not a language code
gettext: poqm/it/step_qt.po: qt not a language code
gettext: poqm/ja/step_qt.po: qt not a language code
gettext: poqm/ka/step_qt.po: qt not a language code
gettext: poqm/kk/step_qt.po: qt not a language code
gettext: poqm/km/step_qt.po: qt not a language code
gettext: poqm/lt/step_qt.po: qt not a language code
gettext: poqm/lv/step_qt.po: qt not a language code
gettext: poqm/mai/step_qt.po: qt not a language code
gettext: poqm/ml/step_qt.po: qt not a language code
gettext: poqm/mr/step_qt.po: qt not a language code
gettext: poqm/nb/step_qt.po: qt not a language code
gettext: poqm/nds/step_qt.po: qt not a language code
gettext: poqm/nl/step_qt.po: qt not a language code
gettext: poqm/nn/step_qt.po: qt not a language code
gettext: poqm/oc/step_qt.po: qt not a language code
gettext: poqm/pa/step_qt.po: qt not a language code
gettext: poqm/pl/step_qt.po: qt not a language code
gettext: poqm/pt/step_qt.po: qt not a language code
gettext: poqm/pt_BR/step_qt.po: qt not a language code
gettext: poqm/ro/step_qt.po: qt not a language code
gettext: poqm/ru/step_qt.po: qt not a language code
gettext: poqm/si/step_qt.po: qt not a language code
gettext: poqm/sk/step_qt.po: qt not a language code
gettext: poqm/sl/step_qt.po: qt not a language code
gettext: poqm/sq/step_qt.po: qt not a language code
gettext: poqm/sv/step_qt.po: qt not a language code
gettext: poqm/th/step_qt.po: qt not a language code
gettext: poqm/tr/step_qt.po: qt not a language code
gettext: poqm/ug/step_qt.po: qt not a language code
gettext: poqm/uk/step_qt.po: qt not a language code
gettext: poqm/zh_CN/step_qt.po: qt not a language code
gettext: poqm/zh_TW/step_qt.po: qt not a language code
      

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.