How to reproduce:
1. Open the user's attached "shader_errors" project
2. Reimport the "NewUnlitShader" (in the Project window right-click on the "NewUnlitShader"->Reimport)
3. Close and reopen the project
4. In the Project window select the "NewUnlitShader" Asset
5. Inspect the Inspector (Window->General->Inspector)

Expected results: Errors of the Shader are shown in the Inspector
Actual results: No errors of the Shader are shown in the Inspector

Reproducible with: 2019.4.16f1, 2019.4.23f1, 2020.3.1.1f1, 2021.1.1f1, 2021.2.0a11
Not reproducible with: 2018.4.33f1, 2019.4.15f1

Notes:
- Reimporting the Shader makes the errors appear again