I get the message "achievements cannot be earned in this world." I have read elsewhere that this means that at some point in time cheats were enabled. I have never enabled cheats. I just bought the game. I used the free trial and then unlocked the full game shortly after. I was playing in the same world before and after unlocking the full game. If this is intended behavior, it is not very user friendly. I would like to earn achievements.

As far as I am aware, I never received any message warning me that I could not earn achievements in my world. The first time I ever checked on the settings, "Activate Cheats" was toggled off. I am playing survival mode.