Butterfly-Flower can be planted in hard tile.

This is only happened in the saves that is not compatible with SW and/or HAM.

It is caused by its deployable component missing test:

local notags = {'NOBLOCK', 'player', 'FX'}
local function test_ground(inst, pt)
	local tiletype = GetGroundTypeAtPosition(pt)
	local ground_OK = tiletype ~= GROUND.ROCKY and tiletype ~= GROUND.ROAD and tiletype ~= GROUND.IMPASSABLE and
						tiletype ~= GROUND.UNDERROCK and tiletype ~= GROUND.WOODFLOOR and 
						tiletype ~= GROUND.CARPET and tiletype ~= GROUND.CHECKER and tiletype < GROUND.UNDERGROUND

	if ground_OK then
	    local ents = TheSim:FindEntities(pt.x,pt.y,pt.z, 4, nil, notags)
		local min_spacing = inst.components.deployable.min_spacing or 2

	    for k, v in pairs(ents) do
			if v ~= inst and v:IsValid() and v.entity:IsVisible() and not v.components.placer and v.parent == nil then
				if distsq( Vector3(v.Transform:GetWorldPosition()), pt) < min_spacing*min_spacing then
					return false
				end
			end
		end
		
		return true

	end
	return false
end

Also, its min_spacing is missing too, which is 0.5 in DLC0002 and DLC0003:

inst.components.deployable.min_spacing = .5