I'm extremely sure that it must be from a mod. Could you post some screenshots please, and also maybe make a list of your activated mods?
I can click on the planet's information tab, but if I bring up the "surface" screen, the game crashes to desktop. I'm not sure if continues to do so after the planet has been colonized, or if this planet type can be colonized at all, for that matter.
Screen shots:
Activated mods:
I ISB - ASBM compatibility patch
(-New Ship Classes & More v3.0-)
(re)Member Primitives?
-Epic Explosions (Downscaled Ships Version)
25 More Reactors + New Techs
Additional Traits
Advanced Jump Drives (1.4+)
AlphaMod: Divided Loyalties
AlphaMod: Orbital
AlphaMod: Plus
Animated Asari Portraits - Mass Effect
Animated Quarian Portraits - Mass Effect
Autism Namelist
Auto Build and Improve Buildings ENG/RUS/FRA/GER
BJR - Golden Avian Ships
Beautiful Universe v2.0
Better Subjects Updated
Board That Ship!
Carrier Sections
Cat Portraits Dimorphism
Cinematic Camera
Citadels - Tier 4 Defensive Stations
Cloned
CofH UI - Species Mod Window
Color Coded Pop Status Icons
Complete Eldar Name List
Crystallis Ship Modules Expansion
Downscaled Ships
Dreadnought (Downscaled Ships Scaling)
Emblems: Sci-Fi & Others
Epic Explosions
Ethics&Government + AlphaMod
Ethos Unique T&B AlphaModded
Even More Demanding Wars (Warscore Adjustments)
Expanded Hulls - Better Sections
Expanded System Names
Extended Emblems
Extended Traits
Extra Events
Fallen Empires Expanded
Faster Genetic Engineering
Flags: Emblems & Backgrounds
Food Imports/Exports
Fortress XL
Fungoid Protoss Ships
Galactic Dawn: Forgotten Technology
Galaxies Unlimited 1.4+
GeneMod_UI_PlusPlus
Genesis Worlds - Better Homeworlds
Genetic Engineering Buff
Glassing the Planet
Gods and Guardians
Ground Combat Evolved
Guilli's Plantoid Ship Graphics Pack
Guilli's Plantoid Ship Pack - ISBS Doomsday Patch
Guilli's Plantoid Ship Pack - NSC Patch
Gwen's Domesticated Xenofauna
Halo Covenant Species
Homeworld Ethics
IIC - Old Republic Ships
IIC - Revival - Extra Playable Races
IIC - Sith Empire Ships
ISB - Doomsday Weapons & Ships
Icen System Scale and Beauty
Improved Leader Dynamics
Improved Space Battles [Balance]
Improved Space Battles [Graphics]
Infected
Interesting Cities
LEX - Leviathan Events Xtended
Mass Effect - Geth Species
Mass Effect - The Asari Civilization
Milky Way Unleashed
Mod Pack Flag Graphics
More AI Personalities
More Events Mods
More Realistic Star Systems
Multiple Crisis
NSC 3.0 Star Wars Ship models
Natural Selection
No Clustered Starts
Planet Cap Raised
Protoss Species
Remove Aura Graphics
Research All FTL (1.4+)
Researcher Trait 'Fix'
Ringworld Restoration
SD's Better Strike Craft
SD's Durable Ether Drake
Select starting ruler's traits
Shanty Town
Ship Power Stations
Sol Expanded (25 tile Earth)
Star Trek Federation TMP - Ships Standalone
Star Trek Star Systems
Star Wars Empire Ships
Star Wars Pirate Addon
Star Wars Rebel Ships
Stellar Expansion
Stellar Expansion - FTL Enhanced
Stellar Expansion - Genetics
Stellar Expansion - Geoengineering
Stellar Expansion - Strategic Resources
Stellar Expansion - Terraforming
Stellar Expansion - Terraforming (Extreme)
Stellar Expansion - Voidcraft
Stellaris Tycoon Redux
Stellaris: AlphaMod
Svafa's Expanded Species Traits
Systems Alliance (Mass Effect) Ships
TFW's Bunch of Ship Parts
The Belt Updated (1.4 Kennedy)
Ticking Warscore
Titan Laser + Resized Lances
Titan Weapons
UI Overhaul 1080p
Unique Resources
Unique Systems Spawn 100%
War Name Variety (No More Brawls)
XL Cruise Missiles
ZBeautiful Battles
The game does track if a Planet is the "Homeworld" of a species. However that is tracked on a per Species level.
Only that one species has 100% habitability on it, but in turn a Planet tagged as "Homeworld" can not contain a Frontier Clinic or Frontier Hospital (other Habitabiltiy buffs are valid, however).
However what you describe is nothing like that.
Usually only Gaia Class Planets and Ring World Segments have 100% Habitability for every species. Everything else has a Plant Class/Species Preference based value. Could this be a Precursor race home System?
Could it be that you have Synths, so every planet is considered 100% Habitable? In earlier games there used to be a bug, where even Robots would trigger a slightly faulty display.
A screenshoot is nessesary before we can give you a better answer.
See above for screenshots.
I do have a mod active that allows you to choose whether you want to play as an organic or synthetic at the beginning of the game. However, I chose organic, and I've had that active for some time without issues.