Rig problem

Hello!

I have a weight problem. Well, before I added wings to the character and some other tweaks, it was fine, but after I added bones to the wings, I connected the skeleton to the object via “automatic weight”. And moving a given bone deformed practically half of the object. I do not know why. The old Vertex Group was wiped clean before I started adding anything. I also did “Rotation and Scale” and “Clear Parent”.

Video: https://cdn.discordapp.com/attachments/506192731551301659/772501942693134346/2020-11-01_17-42-42.mp4

Put your character in Edit mode.
Open the list of Vertex Groups.
There are 2 boxes at the bottom of the list: Select and Deselect.
Clear any selected vertices
Select a vertex group and click on Select - all the vertices in that group will turn orange. If there are some vertices you don’t want in that group, select them and choose to Remove from the group. Just be careful you don’t remove all the vertices from the group.

First thing I’d say is, check the direction of your mesh normals.

Regardless, I found out why this is happening and working normally.