After upgrading this project, the very first time I opened the scene, it was rendering just grey, and no changes i made to the settings/lighting, etc would solve it. After I closed and reopened the scene, everything rendered normally!

To reproduce:
- download the performance-office.zip project attached to this bug report
- install the latest HDRP package
- open the OfficeRoom scene
- fix any issues that the Rendering Wizard may flag up
- notice that rendering is grey in the scene
- switch to Albedo in the scene view mode and notice that it does render something
- but switching back to shaded makes the scene all grey again

Workaround: if you close and reopen the scene, everything will render normally!

I tried regression checking to 2019.3.0f3 and HDRP 7.1.6 and I still get the grey scene the first time i install the package.
Regression checking further back is impractical, as this project is not compatible with older versions.

This project was made after removing reference to local SRP packages in Packages/manifest.json files.
It is in an intermediate state where a HDRP asset still exists in the project and is referenced in the graphic settings, but HDRP is not imported.
Here are some findings :
- Packages/manifest.json does reference VFX graph, when it shouldn't as it is a dependency of HDRP
- Removing the reference to the HDRP asset at m_CustomRenderPipeline in ProjectSettings\GraphicsSettings.asset before opening the project make the rendering work properly
- Alternatively, if you open the graphic settings, and then do "File/Save Project" after opening the project, it will also fix the reference to the HDRP asset, and make rendering work after importing HDRP
- If the asset reference is not cleaned prior to import of HDRP package, opening the graphic settings appeared to fix the rendering

This issue seems to have been reported on the Unity forums as well: https://forum.unity.com/threads/hdrp-no-longer-compiles-game-and-scene-views-are-gray-and-black.794562/#post-5291976