Etherian Space Program , three advices I can give you
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1)- First of all...
I've seen this like a million times. Its usually caused when a parent body's code is broken/miscoded.
2)- If you have problems with your planet pack, you don't have to reinstall the game, simply delete your Planet pack and install a whole new one from zero.
3)- You must NEVER, under any circunstance, changing the name of the Earth. You can edit it as much as you want (hell, I made Earth an asteroid once), you can make it orbit the body you want, but you ALWAYS need to have something named EARTH on your Planet pack. This will tell the game where to launch/recover from.