There is a translation error in the error message that appears when you try to “save all attachments”, but a file with the name already exists in the target folder.
In English, it’s this error message:
The German message looks like this:
The sentence “Destination folder already contains a file named [filename].” is not translated correctly into German. Translated back into English, it says: “The folder with the name [filename] already exists”.
It should say:
“Der Zielordner enthält bereits eine Datei [filename].”