Why is the testing cheats enabled true not working?

Mia - Updated on Apr 15, 2017 at 04:29 PM

I used the testingcheatsenabled true cheat just yesterday, but now when I type it in it doesn't work. I've tried using testingcheatsenabled on and it wouldn't work either.
I then tried using capital letters on the cheat, yet it still wasn't working.
What do I do?