Ok, so I finally completed the "1 hour special: Maitreya Lara clothing Tutorial (Dev kit included)" tutorial, and I decided to retry the tutorial on a mesh that I created from scratch by myself (Thanks for the tutorial by the way, Zero).

I reached the point where you have to transfer weights. For some reason, after retrying many times, the weights will only transfer to only the top or the bottom, depending on which part of the body (top or bottom) I clicked first. For example (as my attached picture will show), even if I selected both parts of the body, when I click the bottom first, the transfer of weights only goes to the bottom. When I try to rotate the arm or torso of the armature, the sleeves of the dress doesn't move with it and the torso becomes completely distorted.

Any idea of what I could be doing wrong? Sorry if the answer to the question is obvious. I'm new to all of this. Thanks for any replies.

Hi shameronc :)
I don't know if you still have this problem but maybe you want to join the body first before transfering weights.