Okay, make sure you ACTUALLY repointed the type chart, as in, replaced all the pointers to it. And also, double check you put the right hex for "Fairy Dark 2x" in the chart. Also double check that you are actually using a Fairy type move. If it doesn't work after all that, I think you should redo that entire process just to be extremely sure. If it doesn't work after all of THAT. Well, we'll see when we get there.