If a project contains Krita authored .psd files and the project is upgraded from Unity 2020.3 to Unity 2021.3, the Sprites in the .psd file gets new Sprite Ids and consumers of these sprites loses their references.

How to reproduce:

1. Create a .psd file in Krita, save it to disk and rename the file ending from .psd -> .psb
2. Create a new project in Unity 2020.3 and add the .psb file into the project
3. Drag a Sprite out from the .psb file into a scene and save the scene
4. Relaunch the project in Unity 2021.3 and view the scene with the Sprite in it

Expected:

Sprite is visible in the scene

Actual:

The SpriteRenderer has a missing reference in the Sprite property.

Tested with: 2020.3.33f1 & 2021.3.0f1