Windows XP/Vista support is ended
The Windows XP/Vista systems' support has officialy ended by MTA in this year's September in order to have the most recent updates of CEF (Chromium Embedded Framework).
Basically the CEF dropped the xp/vista era and not MTA but they had to follow it since there are too many developers who use CEF as their GUI or gamemode system and they want to get all the features in time.
There is still an old version of 1.5.7 which still can be installed to xp/vista but players will notice that they can't update their clients and they can't connect to a server whose minclient-version is ahead of the last supported version.
CEF is a way to use weblanguages not only in browsers but in desktop and in any applications. Tons of million products use it for the better design opportunities just like League of Legends which is also dropped the xp/vista support in this week for the same reason as MTA.
If you are using Discord for example thats a HTML,CSS,JS frontend side application running in Electron (NodeJS API) and Electron is a CEF based API.