“UnityException: Load is not allowed to be called during serialization” error is thrown when using Resources.Load method in a serialized class

Reproduction steps:
1. Open the attached “ASDQWE” project
2. Open the “Assets/Scenes/Menu.unity” Scene
3. Enter the Play Mode
4. Press enter multiple times to progress the game
5. When the “BaseTemplate.unity” Scene has been loaded, exit the Play Mode
6. Enter the Play Mode
7. Observe the Console Window

Expected result: No error is thrown
Actual result: “UnityException: Load is not allowed to be called during serialization” error is thrown

Reproducible with: 2021.3.28f1, 2022.3.5f1
Could not test with: 2023.1.5f1 (two “error CS0246: The type or namespace name 'ShadowCaster2D' could not be found” errors), 2023.2.0b1 (“error CS0266: Cannot implicitly convert type 'UnityEngine.Vector4*' to 'UnityEngine.Vector2*’”)

Reproducible on: Intel macOS 13.4

Note: The error does not pause the Play Mode