I'm playing Mrrshan

I have just captured a Psilon planet. I bought a colony base and as soon as it finishes, it gets scrapped for 100 BC.

What Is the reason for this?

There are 2 colonisable planets.
There is a gnolam colony and a few warships
I have a warship in the system
All of the Psilon colonists are still angry.

Perhaps the Gnolam warships are blockading the system.

The only other reason I can think of is your empire is in the red...I've never seen anything auto-scrapped otherwise.

I have 2000 BC in the bank.

Does the bug happen at other colonies?

I haven't tried it in others.

I think it's a bug. I found another a few turns later:

I am allied with the Alkaries and they are allied with the Humans.

The humans declare war with me.

The Alkaries contact me and tell me that in the spirit of our alliance, THEY are declaring war on the Elarians. A race that was eliminated a long time ago.

I close the audience, the turn summary says that I am now at war with the Alkaries.

Rant: By the way, those guys are real scumbags. Twice they used our alliance to get me to declare war, only to make peace with the other party on the next turn and leaving me stuck because my newfound enemy doesn't want to talk. And NOW they declare war.

It actualy turns out well because I'm playing on hard, I just finished turning Orion into a Ship factory and I'm now at war with 3 people so there are a lot of ship battles. It's awesome.