As of today, with patch 220.127.116.11, Windows XP is longer supported.
The minimum version of Windows the game now supports is Windows 7.
We have tried to keep the game compatible with Windows XP for years but it's just no longer possible for us to do it. Windows XP is a 19 years old Operating System and Microsoft officially stopped supporting it in 2014. It is time to move on.
Sorry for the inconvenience