Add a new language to Indico 2.2

I renamed the folder name to “zh_hans_CN”. Then I re-run

indico i18n compile-catalog
error: indico/translations/es_ES/LC_MESSAGES/messages.po:2640: placeholders are incompatible
error: indico/translations/es_ES/LC_MESSAGES/messages.po:2648: placeholders are incompatible
2 errors encountered.

I still did not get messages-js.po messages.mo messages.po files. I cannot see the translation.
I am setting up a dev version, I have encountered a lot of problems. I am stupid. I do not know how to fix them.
Such as the ticket The problem about the webpack watcher when setting up development version installation p

Thank you!!