no additional languages selectable

I can`t select any dditional language under Files->Settings->Interface.
There is only English installed and the INstall Icon is greyed.
This happends after a reinstall of SFTP.
Wehre could I download additional language files?
Thanks for any hint.
Best regards

Hello mb,
for this I have to purchase a new licens cause 6.0.2122 was the latest which my maintenance period accept.
Any other possibilities?

This version has been superseded by the latest version.