I included "reset bind pose" in the process with reference to your advice. After modifying it in many ways, it works but I'm not sure if this is the right way. Here's my process.

Go to the Binding tab, disable the skin object, go to the Adjust tab, and adjust the components and controllers to the desired scale. (IK-Chain tag is on the joint, so I adjusted the depth to the same rate.) Then come back to the Binding tab, run "reset bind pose" on the weight tag, and activate the skin object again. Then the mesh did not get twisted.

I think there is an easier way than such a cumbersome procedure, I wonder if this procedure is correct.

Have a nice trip. I can't wait to finish this project and rest.

@Dr-Sassi

Hi. Thank you for your response.

Here's a link to the project file and a video. In the video, I simply applied the rotate key animation after scaling it to 10.

https://works.do/IFnaZj4

Hi, I've used the character object provided by Cinema 4D to rig the bird.

I'm done binding and weighting and I'm trying to change the scale to apply it to other scenes.
As I saw in some tutorials, I disabled the skin objects, grouped the mesh and the character objects to scale up, then ran "set bind pose" on the weight tag and enabled the skin objects again.

There was no problem in looking at it, but when I simply rotated it around for testing, the mesh got twisted. I roughly re-rigged with another new bird model and did the same thing to find out where the problem came from, but the same problem happened.

What should I do? I've been trying to fix the problem for days and now I'm tired.