If auto-upgrade is enabled for an account and a user attempts to log in using an older version of Firefox (older than version 41), the user will be prompted to upgrade to Registered Computer 1.16, but will be unable to complete the installation. This will occur every time the user attempts to log in with the older browser if auto-upgrade is enabled.
The Registered Computer 1.16 credential is not supported on older versions of Firefox. However, Firefox cannot distinguish between the Registered Computer 1.12 and 1.16 credential extensions.
To avoid this issue, the user should upgrade to the latest version of Firefox or not select the Remember me on this device link.
If the user has started the upgrade process, have the user click Skip, and then log in using another authentication method, like VIP Push or a security code.