The Chrome Browser version 55 is the latest version of the browser and it has some important security oriented updates, as well as performance enhancements. To encourage users to upgrade to the latest version of the Chrome Browser, Google has announced that it will be showing a banner on top of Gmail for those who are using Chrome version 53 or previous versions. The banner will start showing up from 8 February, 2017.
The users most likely to be affected are users who are still using legacy operating systems from Microsoft such as Windows XP and Windows Vista. Microsoft does not maintain these operating systems any more, and Chrome version 49 is the latest version supported on these operating systems. Google is encouraging users to migrate to newer and more secure operating systems. Using Gmail on the old operating systems with outdated browsers is a risky operation and could potentially compromise the security for the end user, which is why Google is taking steps to stop access to Gmail on older versions of the browser.
Gmail will continue to work on Chrome version 53 and below till the end of the year, although with the banner. Those users who still do not move to later versions of the browser by the end of the year, will see Gmail reverting to a simpler, HTML version of the service, from as early as December 2017. Google is encouraging system administrators to migrate their users to newer versions of the browser, with an alert that it might be necessary to get a newer operating system as well.
Google does not normally make announcement on when support for Gmail will be stopped on older versions of Chrome. This is because of the current supported browser policy by Gmail, only the latest and most secure versions of browsers are supported. Google has made an exception in this particular case, as it can affect a large number of users who are on Windows XP and Windows Vista, and still want to access Gmail through these old operating systems.