Unable to create worlds: The worlds won't load in Edit In Game on my new PC

I would just try saving after you've removed the 2 files mentioned above - do not delete - but put somewhere easy to find so you can put them back after you are finished with your world.

I can't remember if the game regenerates a new DCCache folder, it might - it would be empty tho, if you've taken out the folder that did have your store content.