Hi,
I did everything like in the new
An iDiot's Guide To iMessage and came up with stable credentials but still a 12 digits code to call Apple support with.
Being in France, I called the French support. The IVR asked for my Mac S/N, then the guy did the same, I gave it, which he didn’t find after having me repeat it twice and counting how many letters and digits it had. Then he checked my name and Apple ID, checked that I was able to connect to System Preferences/iCloud, did something, asked me to try to connect to iMessage, and asked me for the 12 digits code. Then he asked me to connect also to Facetime, which I had never used, and the same 12 digits code poped up. At some time he put me on hold maybe to get advice.
I was very calm, and kept telling about the code and my AppleID. He seemed to me either puzzled by the situation, or maybe they are now aware of us hackintoshers, though he never asked me about my computer type (I created a 27" iMac 13.2 identity). It lasted around 20 minutes, and at the end, the guy just asked me if I was calling from France, and dropped the call !! Surely not part of his best practice and Apple values…
I may try another time in a few days. Any advice here ? Maybe call the US support ?