Translation of site interface not available
I have two content sections (German / English). However I can only translate my strings into English. The German translation is not available.
I have tried to clear the cache and reload the strings but nothing changed.
However it seems to work if I change the country to Austria for example. So how do I get the German German (de_DE) to work? I already deleted the whole content sections and added them again but still not possible to translate German strings. Any suggestions to fix this?