title: AWS MFA Issue Please verify your MFA serial number is valid and associated with this user
body: <p>Been using <a href="https://github.com/broamski/aws-mfa" rel="noreferrer">https://github.com/broamski/aws-mfa</a> to handle MFA for AWS with much success. I have three users who get the following error when trying to use it:</p>
  <p><code>An error occurred (AccessDenied) when calling the GetSessionToken operation: MultiFactorAuthentication failed, unable to validate MFA code.  Please verify your MFA serial number is valid and associated with this user.</code></p>
  <p>Any ideas on how to troubleshoot? I have 20+ users that are just fine; I'm at the end of my rope on what these three users are doing different. I've verified that they didn't do a bad copy-pasta into their credentials file.</p>