nevermind. it was another mod. :O

creative mode.

Impossible de charger les mods : Error while loading item prototype "creative-mod_enemy-object_colony-chu1-composite-decrepit-top" (item): Key "icon" not found in property tree at ROOT.item.creative-mod_enemy-object_colony-chu1-composite-decrepit-top.icons[0]
Modifications: Creative Mod › Renai Transportation

nevermind. it was another mod. :O

creative mod .seems to be incompatible with colony builder.

i use creative mod to unlock everything to test mod before using it hehe

By looking at the error message I assume the creative mod copies some of the entities of my mod which I use to spawn colonists with. This type of entity is used by vanilla Factorio to spawn enemies. These entities have no icon specified because they are not visible to the player anyway. Maybe that's the problem.