This issue is when I spawn the game with AI in various degree of development, the way I like to play the game.
I have to go onto the editor and check all the worlds and make sure they are at least on a +20 colonization value for the worlds they settled.
If there is an issue with rare colonizable (low quality worlds) then I think the game generation need to modify a few worlds to help the AI settle the world they need. This issue still exist in normal rarity of high quality worlds, but less of an issue.
I also still see issues with independent worlds... Humans often get worlds at around 51% quality which is too low to settle them... at least in the early and mid game. I have seen a few other with the same issue.
I would really like to not have to use the editor and spoilt where everyone is just to have a normal game...
I really like to have low quality worlds in large galaxies, otherwise research simply become too overwhelming and income quickly raise to insane levels. I also don't want twenty major empires in my games, but rather around ten empires in varied states of development at the start of the game.