This is something that happened to a friend who shared a paid card disc with me. Apparently, he had exported it from a scene but forgot how the plugin that allows you to extract them works. Before doing so, you have to remove any type of bone modification, collisions, or shape blending that the model may have in that scene (basically everything that comes with KKPE from Chara Studio). I would even recommend disassociating the dynamic bone, which is widely used in scenes. It's something like leaving it in its base pose (T POSE), because the Hanazono Hahari model he shared with me had a bust that was sky-high and arms that looked like spaghetti when he put it in Chara Maker. That's because ABMX was saved that way.
I apologize if this isn't the case, but I'm sharing my experience with you in case you have the scene with the model you want and can export it successfully. 🧐