Every time I equip it, it just gives me the default brown fur and doesn't show my accessories. Has something happened to the coding for it?

If you're trying to equip something in Bootcamp, the preview refreshes to show your mouse wearing nothing since apparel is disabled in Bootcamp.

Otherwise, I have no idea what it could be.

Ohh! It could just be when you log in it doesn't show the fur you were last wearing! This happens to me ALL the time. I don't know why though. All you have to do is change your outfit to another fur, refresh, then log in again and change your outfit to the fur you'd like!

Is the heart fur the purple one, Or the one with the heart on its butt that is almost completely white? Because the almost white one works for me

I do not own the Heart fur, but this looks like a slight bug to me.

/nude ?

Nah there is a problem with loading the outfit you login with that occurs sometimes, that makes only that particular outfit show a brown mouse. All you have to do is change a color or change one accessory, and it should all reappear. Even just changing the last digit of a hex color code will bring it all back.

Every time it's equipped, however? I don't think that's the case here.