WTF MY EEVEE IS NOT EVOLVING INTO SYLVEON!

[Pikachew Tobacco]

Some games have a glitch that prevents Eevee from evolving into Sylveon. I'm not sure if this is temporary or permanent. The only solution is to trade it to a different game and evolve it there. This will always work with X and Y. Trading to another ORAS game has been known to work as well. Make sure the ORAS you're trading to can evolve Eevee into Sylveon. Hope this helps.

[Brotres]

First, you'll need to teach your Eevee a fairy-type move, but that's not enough! You also need to make it very, very happy. The solution lies in the new Pokemon-Amie system, which allows you to play and pet your Pokemon. In order to evolve to Sylveon, you're going to need to have all three sections in Amie--Affection, Fullness, and Enjoyment--up to max. Filling up Enjoyment is as easy as playing a bunch of minigames, and that will give you enough snacks to make sure your Pokemon's Fullness is max.

Once you've maxed out all three of these teach your Eevee a fairy move, level up, and--bam! You're the proud owner of a shiny new (well, not actually shiny, most likely) Sylveon! Take note to make sure your Fullness is maxed going into battle, since it can go down over time (or between battles), but as long as you follow these instructions you'll have a Sylveon after about an hour or two's work!

[Bannana Muffins]

have you tried, playing a game & feeding it poke puffs
then repeating a few times over?

... Muffin has spoken.

[Kallen-chan]

Pikachew Tobacco

Some games have a glitch that prevents Eevee from evolving into Sylveon. I'm not sure if this is temporary or permanent. The only solution is to trade it to a different game and evolve it there. This will always work with X and Y. Trading to another ORAS game has been known to work as well. Make sure the ORAS you're trading to can evolve Eevee into Sylveon. Hope this helps.

I've seen posts on other sites that back this up. Some people can't evolve their eevees to sylveon on ORAS, while others can.

Maybe we can get a patch that fixes this weird glitch.

[Fat Anime Tiddies]

Have you tried ******** it?