Error while installing worlds

Also the installed worlds don't show up in game when picking new game. On top of not showing in game once installed there's another issue. The installed content resets once I open the launcher again and I have to do the installation all over again. I don't understand what's going wrong. It's been so long since I've used downloadable content I don't remember how this works but I don't think I ever had this issue before. Hopefully someone can help me out so I can use these worlds in my game.