Update pop up

Users may see an update available pop-up shown below.

individual browsers control when the update occurs. After login, typically it updates to the next release automatically, but if there have been multiple updates since the last time they will get this. Also, If they haven’t closed their browser tab at all they will get this. 

Other users aren’t seeing this for that reason because it transparently happens when they log in. It all depends on the browser and the user's tab management habits.