Question HDRP Project - Game & Scene Views Now Black

Hi--

I've been working with the HDRP without any issues. It would run perfectly in editor. However, a build would crash within 5 seconds of running. I once eventually got an error message saying it couldn't read certain memory. So I tried nuking the Library to force Unity to rebuild it, as that often fixes odd issues.

After rebuilding the Library, there were errors when Unity tried compiling the HDRP shaders again, and now the Game View and the Scene view are black. Nothing shows up in even the Scene view, unless I select an object and set the window into Wireframe. Only certain objects will show up with bounding boxes or their usual wireframe elements, such as lights. For all objects selected, the gizmo shows up, but nothing else. This project worked perfectly and then suddenly doesn't anymore.

I had a similar issue when trying to open The Heretic character and other older HDRP projects of my own that used to work perfectly.

I'm using Unity 2020.3.25f1, DX12 or DX11, Windows 11.

Fortunately, I had a backup of the Library and dropped it back in, and now it works fine again. Amazingly, now new builds work without crashing at rock-solid framerates. WTF...

But since this happens with older projects, I'm worried about code-rot with this project now going forward and wondering what even happened so I can try to prevent this again.

Any ideas?