I cannot sign into AWS account. The AWS management console accepts password but then throws 400 error before getting to MFA. Link to Support takes me to login again, haha. I cleared cache and cookies for all of time. I tried different browsers and devices. 
CodePudding user response：
I had the same problem and the same unsuccessful attempts to resolve. It now appears to be fixed at least for me. Hopefully for you all as well.
CodePudding user response：
According to AWS support, they said that I have two AWS accounts. That means my Amazon.com account also counts as an AWS account I guess. Both have the same email address, e.g. [email protected]. Therefore, the below StackOverflow link fixed my issue.
- I just had to modify my Amazon.com email to include amazon so if it was [email protected], then I needed to change it to myemail [email protected]. Do this by logging into Amazon.com, then navigate to Your Account > Login & security
- Don't worry, you don't actually need to create an email for myemail [email protected]
- Seems like Amazon.com removes the amazon and continues to treat it as [email protected] as far as I've noticed so far. You are still even allowed to log into Amazon.com with [email protected] without adding the amazon
After doing this, I was able to log into AWS account as usual. =)