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 lintian 's PO files:

gettext: t/recipes/checks/cruft/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/citetitle.po: can't guess language
gettext: t/recipes/checks/cruft/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/comments.po: can't guess language
gettext: t/recipes/checks/cruft/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/partialtranslation.po: can't guess language
gettext: t/recipes/checks/cruft/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/soundjuicer.po: can't guess language
gettext: t/recipes/checks/debhelper/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                              Message conversion to user's charset might not work.
t/recipes/checks/debhelper/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/debhelper/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/debhelper/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/debian/copyright/dep5/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/citetitle.po: can't guess language
gettext: t/recipes/checks/debian/copyright/dep5/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/comments.po: can't guess language
gettext: t/recipes/checks/debian/copyright/dep5/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/partialtranslation.po: can't guess language
gettext: t/recipes/checks/debian/copyright/dep5/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/soundjuicer.po: can't guess language
gettext: t/recipes/checks/debian/copyright/dep5/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                          Message conversion to user's charset might not work.
t/recipes/checks/debian/copyright/dep5/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/debian/copyright/dep5/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/debian/copyright/dep5/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/debian/copyright/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                     Message conversion to user's charset might not work.
t/recipes/checks/debian/copyright/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/debian/copyright/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/debian/copyright/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/debian/debconf/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                   Message conversion to user's charset might not work.
t/recipes/checks/debian/debconf/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/debian/debconf/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/debian/debconf/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/debian/debconf/po-debconf-general/build-spec/debian/po/English.po: can't guess language
gettext: t/recipes/checks/debian/debconf/po-debconf-general/build-spec/debian/po/de.po:1: keyword "This" unknown
t/recipes/checks/debian/debconf/po-debconf-general/build-spec/debian/po/de.po:1:5: syntax error
t/recipes/checks/debian/debconf/po-debconf-general/build-spec/debian/po/de.po:2: keyword "all" unknown
msgfmt: found 3 fatal errors
gettext: t/recipes/checks/debian/debconf/po-debconf-general/build-spec/debian/po/templates.pot:25: missing 'msgstr' section
t/recipes/checks/debian/debconf/po-debconf-general/build-spec/debian/po/templates.pot:30: missing 'msgstr' section
msgfmt: found 2 fatal errors
gettext: t/recipes/checks/debian/patches/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                   Message conversion to user's charset might not work.
t/recipes/checks/debian/patches/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/debian/patches/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/debian/patches/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/debian/po-debconf/invalid-potfiles-in/build-spec/debian/po/zh_CN.po:34:7: syntax error
msgfmt: found 1 fatal error
gettext: t/recipes/checks/debian/po-debconf/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                      Message conversion to user's charset might not work.
t/recipes/checks/debian/po-debconf/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/debian/po-debconf/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/debian/po-debconf/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/debian/po-debconf/po-debconf-general/build-spec/debian/po/English.po: can't guess language
gettext: t/recipes/checks/debian/po-debconf/po-debconf-general/build-spec/debian/po/de.po:1: keyword "This" unknown
t/recipes/checks/debian/po-debconf/po-debconf-general/build-spec/debian/po/de.po:1:5: syntax error
t/recipes/checks/debian/po-debconf/po-debconf-general/build-spec/debian/po/de.po:2: keyword "all" unknown
msgfmt: found 3 fatal errors
gettext: t/recipes/checks/debian/po-debconf/po-debconf-general/build-spec/debian/po/templates.pot:25: missing 'msgstr' section
t/recipes/checks/debian/po-debconf/po-debconf-general/build-spec/debian/po/templates.pot:30: missing 'msgstr' section
msgfmt: found 2 fatal errors
gettext: t/recipes/checks/debian/rules/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                 Message conversion to user's charset might not work.
t/recipes/checks/debian/rules/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/debian/rules/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/debian/rules/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/fields/description/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                       Message conversion to user's charset might not work.
t/recipes/checks/fields/description/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/fields/description/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/fields/description/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/fields/package-relations/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                             Message conversion to user's charset might not work.
t/recipes/checks/fields/package-relations/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/fields/package-relations/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/fields/package-relations/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/fields/standards-version/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                             Message conversion to user's charset might not work.
t/recipes/checks/fields/standards-version/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/fields/standards-version/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/fields/standards-version/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/files/contents/line-length/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/citetitle.po: can't guess language
gettext: t/recipes/checks/files/contents/line-length/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/comments.po: can't guess language
gettext: t/recipes/checks/files/contents/line-length/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/partialtranslation.po: can't guess language
gettext: t/recipes/checks/files/contents/line-length/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/soundjuicer.po: can't guess language
gettext: t/recipes/checks/files/source-missing/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/citetitle.po: can't guess language
gettext: t/recipes/checks/files/source-missing/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/comments.po: can't guess language
gettext: t/recipes/checks/files/source-missing/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/partialtranslation.po: can't guess language
gettext: t/recipes/checks/files/source-missing/cruft-gfdl-invariants/build-spec/orig/src/oldfalsepositive/soundjuicer.po: can't guess language
gettext: t/recipes/checks/languages/python/obsolete/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                              Message conversion to user's charset might not work.
t/recipes/checks/languages/python/obsolete/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/languages/python/obsolete/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/languages/python/obsolete/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
gettext: t/recipes/checks/maintainer-scripts/ldconfig/legacy-debconf/build-spec/debian/po/fr.po: warning: Charset "CHARSET" is not a portable encoding name.
                                                                                                                                                Message conversion to user's charset might not work.
t/recipes/checks/maintainer-scripts/ldconfig/legacy-debconf/build-spec/debian/po/fr.po:61: end-of-line within string
msgfmt: found 1 fatal error
gettext: t/recipes/checks/maintainer-scripts/ldconfig/legacy-debconf/build-spec/debian/po/lang.po: can't guess language
gettext: t/recipes/checks/maintainer-scripts/ldconfig/legacy-debconf/build-spec/debian/po/sample-file.po: can't guess language
      

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.