Just posted by the author of the Activator at his website:
"Sorry, but unfortunately the activator method will not longer works because the dev implemented an internal whitelist (not blacklist). This list contains the SHA256 hash of valid license keys. If the generated key is not in that list, it will be rejected.
Other alternatives that may work are loaders or hooks, but it's a trial and error. If I have some time soon, I'll try to make some tests with a new fix based on one of these methods.