Failed to execute game client. Message when Lauching the game.

First update windows ( you will need Visual C++ and netframework updates )

Fresh install game as described here : 
https://forum.z8games.com/discussion/325292/file-modifications/p1

If you will keep have problems , print screen the error and send a support ticket where to attach image and dxdiag.txt as .zip or .rar archive ( you can't directly attach a .txt file )

P.S. In case you don't know how to get dxdiag.txt file , see this : 
Dxdiag
https://help.z8games.com/hc/en-us/articles/38953937304347-How-do-I-perform-a-Dxdiag-and-how-do-I-get-the-file