Sorry for this taking so long. All issues related to UTF-8 should now be fixed. New Godot editor and extension builds are currently running on GitHub. Should be done in a few hours. You can then download them here.
https://esotericsoftware.com/spine-godot

kBlankii In addition to what Spinebot said, please also pay attention if you're performing the binding or editing of your mesh in animate mode instead of setup:
https://esotericsoftware.com/blog/Mesh-weight-workflows#Be-mindful-of-when-you-bind-meshes-to-bones

Testing carelessly in setup also may cause it (the paragraph under the previous in the article I linked above)

If you accidentally deform a mesh, the quickest way to reset it is find a bone bound to the mesh that didn't cause movement of your vertices between setup and animate mode, change the weights of the affected vertices 100% on said bone, then in setup mode you can press "Update" in the weight panel to save the new bone configuration for the given mesh, and change the weights again to how you actually need them.

You can do it in the editor. The physics constraint sees the changes in the world transform since last time it was applied and it causes the bones to "lag" behind, then catch up using forces. When you move your camera bone, it affects the physics constrained bone. When all the constraints are applied, the camera bone movement affects physics -- not what you want.

The trick is to use a transform constraint where the camera bone X and Y translation is constrained and the target bone is what actually moves the camera. Next, place the transform constraint in the constraint order so it happens after the physics constraint (ie place it lower).

This way the world transforms are computed, but the camera bone hasn't moved yet, then the constraints are applied. The physics constraint is applied first, so it sees the world transforms at that time, before the camera bone moves. Later in the constraint order the camera is moved by the transform constraint, but the physics constraint never sees that movement.

kBlankii Thank you for providing us with the repro project! I was able to reproduce the crash. However, when I assigned SpineSkeletonDataResource to SpineSprite and it did not crash, at least the filename was displayed correctly, but the one you provided was garbled. The following error was also logged in the Output Dock:

Resource file not found: res://spine/露露.png (expected type: )
  spine_godot/SpineAtlasResource.cpp:160 - Can't load texture: "res://spine/露露.png"

So I tried to see if it would load successfully if I changed the filenames, and it did:

The configuration of the skeleton itself has not been changed, so the names of the skeleton, bones, slots, and referenced images contain Chinese characters. I will update the issue later based on this, but for now, I would appreciate it if you could try to avoid using Chinese for animation names and exported file names as a workaround.