Not being able to send the weight paint we edited in Blender into Character Creator.

I created a character in Character Creator and made an outfit for it. For the skirt-like parts at the bottom of the outfit, I initially tried to add extra bones, but I couldn’t find any way to do it. Later, the Reallusion Support Team told me that it’s not possible because the character’s main skeleton cannot be changed. They suggested another method — importing a pre-rigged skirt instead. So, I did that: I separated the skirt, imported it into CC with bones, and attached it to the pelvis bone. However, as you can see in the video, a separation or gap issue occurred. I know I can fix this with weight painting, so I sent it to Blender via the Blender Pipeline, did some test weight painting, and when I clicked ‘Go CC,’ Character Creator closed immediately without any response, just as shown in the video. Could you please help me with this?

Video Link : https://youtu.be/sSYhbjvmzIQ