Template has a bug, namely with Image. If you save the prefab with TextureAsset and SpriteAsset, then remove Texture and replace it with Sprite, while retaining only the addition of Sprite, but not saving that Texture was removed, you will not be able to put either sprite or texture.
However, this is not the main thing, with this bug, I was able to completely destroy the project.
It happened like this: I changed my entire UI from Texture to Sprite and noticed a bug that I wrote about above. After trying to fix this problem by removing the Element component and adding it again along the way, putting the sprites I needed, I accidentally stumbled upon this bug, in which the editor was broken.