On performing Undo and Redo operation with Tile Palette up to "Undo Create to Prefab" and "Redo Edit Palette" then it causes the editor to crash, Refer attached video.

Steps to repro:
1. Create a new Project with 2D Template
2. Window > 2D Tile Palette > docked
3. Create New Palette
4. Drag and drop Sprite in the New Palette > Save
5. Enable Edit mode and Draw Sprite in the Palette
6. Undo up to "Undo Create to Prefab"
7. Redo Edit Palette

Actual Result:
Editor crashes on performing Undo and Redo operation with Tile Palette

Expected Result:
Undo and Redo operation is performed gracefully

Reproducible in:
2020.2.0b4, 2020.2.0a15

Working fine in
2020.2.0a14, 2020.1.7f1

Environment:
Occurring on Windows 10 & macOS 10.15.