Application.UpdateScene indefinitely for a new project


I’m stumped.

A colleague usually has very slow projects. She’s a 3D modeller, we at first thought it was just vertex count, but recently i was fixing some errors in her scene and her project kept on hanging on Application.UpdateScene after a restart.
So, I made a new HDRP project, to later copy the relevant folders into and subvert the problem. However, the new project, without anything in it, is also hanging on Application.UpdateScene.
I did manage to make a new project with the 3D rendering pipeline that did load correctly. I can load older projects made with the HDRP. I just can’t make a new project.
I already cleared the GI cache (which was indeed full to the brim). Anyone else have any ideas?

For anyone wondering about the result, our specific problem related to the folder that the project was made in. This was a workspace to a plastic SCM repository. We’re still looking for a solution, but for now rebuilding it away from that folder seems to at least allow continuation of work.