Ok, I updated my game to version 1.02.53321. I was able to defeat the Xraki from Earth, Pinthi, and Tywon but I have yet to defeat them from the Mu'Kay and get the new strain. I am at Alpha Repeculea and just defeated the Xraki from the Tywomia system. In looking at the sector map, the Xraki occupy space indicated by the big red exclamation mark. In my case, they are at the Mu'Kay system. They are not located in the Sol system. However, once I move a little bit in the Alpha Repeculea system, the game ends with the above message. This has to be a bug since the Xraki are not in the Sol system (unless the sector map is wrong)!?