We became aware of an issue affecting the previously available German and EU English versions of the digital install downloader for Diablo III, which would not download all the necessary files. If you’ve pre-downloaded the digital version of the game in these languages before 10:00 AM CEST (9:00 AM GMT) on Saturday May 12, you must obtain the new downloaders to be able to install properly once the game is released on May 15. We apologize for the inconvenience, and ask that you please let friends and acquaintances know so they can begin downloading the working installer that’s now available.
Neue Installer hier
es genügt aber scheinbar, wenn man den installer ins selbe verzeichnis laden lässt, wo man schon vorher geladen hatte, da er dann nur einige zusätzlich files laden muss und das geht dann ganz schnell.