I cancelled subscription because of this. I won't pay for being harassed and mocked by the developers.
Killing Artorius was impossible. He froze everyone, jumped to my position and killed me. I was unablee to move or do anything. None of the above suggestions for breaking free worked.
As this thread is from a year ago, we are going to close it out as a necro since some information could be outdated. You are welcome to start a new thread on this subject if one is not ongoing.