My guess is that the Download Access Code is designed to be fed to the Download Assistant, which then Generates an Activation Code that is fed to eLicense Control Center behind the scenes to Activate the Product.
And it feels like whatever server the Download Assistant Connects to is offline, so we get the error.
“kein AC” seems like a translation for “Not an Activation Code” or “Invalid Activation Code.” It isn’t an Activation Code. Apparently, those are generated when you input the Download Access Code into Steinberg Download Assistant.
This is why it is the wrong number of characters when people try to feed it directly into eLCC, and why they get the error message about the eLCC version being too old.
The Download Assistant is erroring out immediately, which is not typical behavior if a server is congested. Usually the connection times out, which causes an error. This is acting as if the server isn’t even online. It errors out within a second or so of you pressing “OK.”