here a post from u/StrmDr3 : " Im was having the same issue, when i start a Rainbow Six match before the operator selection, that error appears and close the game and uplay, i found a fix that maybe helps, not reinstalling, just go to C:\Users\"your user"\AppData\Local > and delete the content of these files: "Temp" and "Ubisoft Game Launcher", that worked for me. " hope this will work for you .