Did my Uplifted citizens suddenly wipe out the entire population of the planet?

I uplifted a species on a world I was settling. The colony was not yet fully established. Shortly after uplifting, I got a notification that the new Husko species was integrating well and everything was going great! After I closed the message, the colony disappeared and I lost the system. The planet surface screen no longer had any pops at all. I got no further message after the "resounding success" dialog.

Is this a bug, or did my new comrades go crazy with their new found intelligence and suddenly and unexpectedly wipe out everything on the planet?

Solution 1:

What happened here is almost certainly a bug caused by the fact, that you uplifted a species while you were in the colonization process.

An uplifted species is added directly into your empire, however the colonization process was running and this confused the game, as you had an incomplete colony, but you were supposed to have full control of the planet. Somehow this caused the game to bug out like this.

Please report this bug (preferrably with a savegame) to Paradox over at their official forums.