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 dnf5 's PO files:

source does not specify a priority
gettext: dnf5-plugins/builddep_plugin/po/zh_Hans.po: can't guess language
gettext: dnf5-plugins/builddep_plugin/po/zh_Hant.po: can't guess language
gettext: dnf5-plugins/changelog_plugin/po/zh_Hans.po: can't guess language
gettext: dnf5-plugins/changelog_plugin/po/zh_Hant.po: can't guess language
gettext: dnf5-plugins/config-manager_plugin/po/zh_Hans.po: can't guess language
gettext: dnf5-plugins/config-manager_plugin/po/zh_Hant.po: can't guess language
gettext: dnf5-plugins/copr_plugin/po/zh_Hans.po: can't guess language
gettext: dnf5-plugins/copr_plugin/po/zh_Hant.po: can't guess language
gettext: dnf5-plugins/needs_restarting_plugin/po/zh_Hans.po: can't guess language
gettext: dnf5-plugins/needs_restarting_plugin/po/zh_Hant.po: can't guess language
gettext: dnf5-plugins/repoclosure_plugin/po/zh_Hans.po: can't guess language
gettext: dnf5-plugins/repoclosure_plugin/po/zh_Hant.po: can't guess language
gettext: dnf5/po/zh_Hans.po: can't guess language
gettext: dnf5/po/zh_Hant.po: can't guess language
gettext: dnf5daemon-client/po/zh_Hans.po: can't guess language
gettext: dnf5daemon-client/po/zh_Hant.po: can't guess language
gettext: dnf5daemon-server/po/zh_Hans.po: can't guess language
gettext: dnf5daemon-server/po/zh_Hant.po: can't guess language
gettext: libdnf5-cli/po/zh_Hans.po: can't guess language
gettext: libdnf5-cli/po/zh_Hant.po: can't guess language
gettext: libdnf5-plugins/actions/po/zh_Hans.po: can't guess language
gettext: libdnf5-plugins/actions/po/zh_Hant.po: can't guess language
gettext: libdnf5-plugins/rhsm/po/zh_Hans.po: can't guess language
gettext: libdnf5-plugins/rhsm/po/zh_Hant.po: can't guess language
gettext: libdnf5/po/zh_Hans.po: can't guess language
gettext: libdnf5/po/zh_Hant.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.