Cannot clean last planet from prethoryn scourge

[Hermarchos]

There is one last infected planet. Their transport ships and construction ships frequently pop up but it shows the planet as occupied by me. I am not able to bombard or to terraform. Collossus isn't able to bombard, too. It shows 1 pop (?). Do you have any clou what I could do?

[RCMidas]

First things first, send an officiai bug report, ideally with the save game attached, to the developers over on the official Paradox forums - the more data they have on these bugs, the easier they will have it when it comes to fixing them.

Second things second, verify the game file integrity and try again.

Third things third, if the Prethoryn ever generate military fleets, let them retake the starbase and their transports invade again. You can then wait another few months until they finish purging the planet, and then go back in to blow it up with your colossus.

If they don't do this and you're on Ironman, you're outta luck. That's a borked run, and yes, I know how frustrating that is. Otherwise, console commands are always an option.

[:D]

press ~ to open the console
type in:
event crisis.211

this forcefully ends Scourge of the Void and the prethoryn crisis altogether

[Hermarchos]

It seems there is no chance. I am on Ironman and they don't generate military fleets, just construction units and transport ships. There is also no power nearby which could start occupying, perhaps the issue existed even before I conquered the starbase.