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 rcmdr 's PO files:

gettext: po/R-Rcmdr.pot:5079:1: syntax error
po/R-Rcmdr.pot:5246: keyword "mststr" unknown
po/R-Rcmdr.pot:5245: missing 'msgstr' section
po/R-Rcmdr.pot:5246:7: syntax error
po/R-Rcmdr.pot:5872: keyword "code" unknown
po/R-Rcmdr.pot:5872:141: syntax error
msgfmt: found 6 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.