I did not discover this, BMSirius of GameFAQs did.

 

 

* The easy way: Drop twice in a row (in other words, once with each character) WITHOUT interacting with any portals. This causes the game to fix itself entirely. If you can't remember if you interacted with any portals in your current character session, just drop three times in a row for safety.

 

 

Here's the link: http://gamefaqs.com/boards/997779-kingdom-hearts-3d-dream-drop-distance/63743281

But they're talking about a glitch caused by TWTNW. A lot of the trouble comes from the Flashback glitch, or at least mine is. I'll still give it a try, though.

I don't know what caused the glitch in my case, but this is the way I fixed it. Worked perfectly.