alien-biomes/prototypes/decorative/vegetation.lua:50: attempt to index field 'map_gen_settings' (a nil value)
stack traceback:
alien-biomes/prototypes/decorative/vegetation.lua:50: in main chunk
[C]: in function 'require'
alien-biomes/data.lua:28: in main chunk

this is a bug with alien biomes, please report it there

FYI, I already made a post about this on Earendel's Discord.

In the meantime, it's an easy solve if you open up the AB zip, just wrap lines 49-51 of prototypes/decorative/vegetation.lua in a nil check, so that that block ends up looking like this.

  for _, proto in pairs(data.raw.planet) do
    if proto.map_gen_settings then
      if proto.map_gen_settings.autoplace_settings.decorative.settings["green-"..plant.name] then
        proto.map_gen_settings.autoplace_settings.decorative.settings["green-"..plant.name] = nil
      end
    end
  end

Isn't it fun being the seeming first person to omit a particular optional property?

well not that many 2.0 mods exist yet that need s surface just to hide some entities on

i can confirm i got the bug with alien biome since new update. i will try your fix bloo