I am having the same issue. I upgraded yesterday and later last night I noticed I had to activate and I laughed. So this morning I looked into it. And here I cant activate. Tried the key M$ provided on the JTP download page and that key will not work either. So what is going on here? Anyone have the answer?
Ok updated I used this key and it worked: PBHCJ-Q2NYD-2PX34-T2TD6-233PK
It is a public key for recovery purposes on the old build.