Importing language pack

[lpu-bot]

Importing a language pack via Administration, Core Functions, Languages doesn't add the language as an active system language (although the system states 'all languages imported succesfully), nor can you update existing (i.e. active system languages) this way (message: 'All languages of this language package are already installed. Please select another package. No import of any kind.'.).

How can one complete the import so that newly added language become an active system language?

And, how can one update a language in bulk?

Thanks

lpu-bot