Decay event was firing even when modifier was removed. Multiple uploads because I'm half asleep and the first two ways I tried to fix it just threw up other issues. Decay events will now simply just check that the correct modifier is actually still present before forcing planet to decay to a lower tier. I have tested, and it should work.

Changed Descriptor version - seems to be working in 3.1.2

Tweaked some text.

Terraforming Candidate modifier will now be applied to terraformed planets which decay into Frozen or Barren class worlds.

Added debuffs to 'Biosphere Stable' modifier, -20% Pop Growth and -20% Habitability.

Updated thumbnail