The data does import, just with warnings. Is there a problem after import?

jhuna11003 The image path is not set immediately after importing a JSON or binary format file, so please fix the image path (이미지 경로):
https://ko.esotericsoftware.com/spine-images#%EC%9D%B4%EB%AF%B8%EC%A7%80-%EA%B2%BD%EB%A1%9C

jhuna11003 Thank you for showing your situation via the video! You must first unpack the texture atlas (skeleton.png) into a separated image for each part.

The following previous thread would be helpful for the procedure for importing skeletons from exported skeleton data: https://esotericsoftware.com/forum/d/18295-how-to-properly-open-packed-texture-file-in-photoshop/2

jhuna11003 The image file icons shown under the Images node are green, so I believe the image placement itself is done in that skeleton. (If the file is not used in the skeleton, the icon will be orange.)
Could you please check if the slots or attachments are hidden? Expand the folded root bone and check it.

I don't see that you expanded your tree to look at the attachments.

All you did is expand the tree. Where are the attachments? Mouse over the meshes. You'll see their outline even if they don't show their image. Zoom in and see what images are there. My guess is your skeleton scale doesn't match the images. When you import the skeleton, set a scale like 0.25, 0.3, 0.5 , etc.
http://esotericsoftware.com/spine-import#Scale

jhuna11003 I think I found the cause! There is a warning about mesh attachments when importing the .skel file shown at 0:48. This message itself is not directly relevant, but from here we can see that the skeleton uses a lot of mesh attachments. Since Spine ESS cannot use meshes, it cannot display a skeleton that uses mesh attachments. If you upgrade the editor to Spine PRO you should be able to display that skeleton correctly.

Ah, sorry I didn't notice it was Spine ESS. You can use the Spine Trial to try an import and see if it behaves like you want, but you won't be able to export.

You can run the skeleton viewer through the editor like this (using the trial, ESS, or PRO):

spine 

---

skeleton-viewer

That may be easier than unpacking an atlas and importing JSON or binary data into Spine.

jhuna11003 I have replied to you in this thread: https://esotericsoftware.com/forum/d/23860-images-appear-like-this

Please do not post the same question twice. We can find your post certainly wherever you post within this forum, so please wait until we reply once you post a question.