The following problem: On the customer's server, I get the message that language packs are not available when I download them. My assumption is that some server settings are blocking the download.
The simplest solution for me was, of course, that I have the language packs locally and can simply upload them.
I uploaded the l10n folder, but in the user settings I get the message The selected language <my language> is not available before the language files are installed.
Can anyone tell me where I may have forgotten to set something? Everything I've found so far suggests that I just need to throw everything into the l10n and it should work.