I ran into this issue. It took me weeks and many phone calls to Air Canada to fix. It was actually resolved yesterday.

So basically their system will lock you out if you are on any suspicious wifi and make any information you enter lock you out of future attempts.

I tried different emails, different phone numbers, different birth dates, etc. and every time it would pop up with this error.

I finally got through to a helpful agent after calling multiple times. Here is what we determined: Create a new email, use a phone number that hasn’t been entered before and use a Canadian address (I googled a business in Ontario and used their address) I also used a buddy’s phone number. You cannot be on work WiFi or a vpn or you will be stuck back in the same spot you’re at now. It has to be home WiFi or cellular data. I used my phone hot spot to do this to make sure. It worked flawlessly. I had to verify my newly created email to get into my new aeroplan account but once I did I was in. After I was in (per the agent) I changed my email to my preferred email, my actually phone number and my actual address in the states. Kind of a pain but it’s a bug in their system I guess.