I too had this error and the Adobe chat rep was most unhelpful. I tried deleting the .dat file as per your instructions and then tried to re-authorize, but got the same error as before. I'm using ADE 4.5. Do you have any other suggestions? I'm using a MacBook Air.
I waited for almost 20 minutes to chat with someone from Adobe and was referred to this forum for help. Five hours later and I am still no closer to resolving my issue. I was told that a team of highly qualified and knowledgable people ran this forum. I am still waiting. Can anyone help me?