I have no issue logging into my gmail from FF57.0.4 nor from Chrome. This is something from Gmail if you don't have it confirmed then this will come up so this isn't a FF issue but a Gmail user setting.

Thanks for the answer.

The problem must come from FF as I don't encounter the same problem with Chrome or Chrome-based browsers with my same Gmail accounts.

Empty your cache and delete all google cookies.

Please let us know if this solved your issue or if need further assistance.

Normally, after you enter the extra authentication, Google will set a persistent cookie so that you do not have to do it again on the same device -- until that cookie is cleared.

There are many ways for this not to go according to plan:

• Using a private window for Google, cookies are dumped when all the private windows are closed
• Using session only cookies
• Setting Firefox to clear cookies when it closes
• Using an add-on that clears cookies
• Using external software that cleans browser data

Clearing all the cache and all the cookies + disabling some add-ons worked. I had to restart a couple of times till it worked. Now, it even works with the add-ons re-enabled.

Thanks for your help.