Starting a new world takes a lot of processing time; it's generating the whole world, so just be patient. It takes a couple minutes, even on "monster gaming rigs".

Start the world, then go make a cup of tea or coffee (whichever floats your boat). Worst case scenario, you come back to a dead guy on the ground... but the death penalty is to drop your items (you start with nothing except your shirt, anyway), and to lose 5% of your skills (which start at zero anyway), so you won't actually "lose" anything but your shirt.