[Forum] Will user login/cookie be retained after upgrade?

[sticheno]

For those of you who have upgraded to a 4 version from 3, possibly you can answer this question which I've been unable to find the answer to. We're planning to upgrade Saturday and I want to know if my users will need to re-login after the upgrade, or if the cookie for my 3.8.4 version will be retained. It's a large forum and with that comes a lot of technically challenged folks for which logging in presents a technical challenge . I'd like to forewarn them if a new login session is required. Thanks to anyone that can shed some light on this question.