eunjoo However, with changes to the 2D Renderer after 2021, Tink Black can no longer be used.
(To be precise, the previously used URP Spine Lit shader appears pink.)

Using 3D Shaders with 2D Renderer was never supported. You always have to use URP/2D shaders when using a URP 2D Renderer. Mixing 2D Renderer with Built-In-RP or URP 3D shaders might look correct in the Unity Editor but may break down in builds or lead to other undefined behaviour.

See the documentation:
https://esotericsoftware.com/spine-unity#URP-Shaders---Extension-UPM-Package

eunjoo Could you also show us some screenshots of the material settings? I want to make sure you have the right shaders and settings.

eunjoo Thank you for sharing the screenshots! The component and material settings appear to be correct, so I guess that the Render Pipeline assets set up in your project are incorrect.

For example, if I were to display skeletons using the Universal Render Pipeline/2D/Spine/Sprite shader with a Render Pipeline asset for 3D renderer, it would look like this:

If the Render Pipeline asset for 2D renderer is set up correctly, it should look something like this:

You say it will be correct in game view, so it could be that some assets are set correctly for some quality levels in the Quality settings in the Project Settings, but other levels are set incorrectly.
Could you please confirm that the correct Render Pipeline assets are being used?

eunjoo I am sorry to hear that the problem still persists. Could you please send us via email a minimal Unity project that can reproduce the problem?: contact@esotericsoftware.com
Please include the URL of this forum thread in the email so we know the context. Then we can take a look at what's wrong.

eunjoo Glad to hear the problem has been resolved! Thank you for getting back to us!