Hey Im a complete noob with modding but I know my way around java. Im trying to generate a vanilla world in the client so far I have
//Minecraft.getInstance().createWorld("worldname", new WorldSettings("worldname", GameType.ADVENTURE, false, Difficulty.PEACEFUL, false, new GameRules(), DatapackCodec.VANILLA_CODEC), null, null);

There was almost no information about .createWorld that I could find and whenever this code is executed it does not generate the vanilla datapack correct (Or to be precise it does not create the vanilla datapack at all) and gives me an error "Errors in currently selected datapacks prevented the world from loading"

If anyone could help me out with this it would be great! Thanks

I figured out the issue

Have to make sure the last to variables are set