Editor crashes after including SAC in my own project

[joostbos]

After I tried the new SAC in a separate project I decided to copy the _StandardAssets and Gizmo folders to my own project. Got compile errors because Cinemachine and InputSystem were not installed. Installed Cinemachine and then InputSystem (I think I chose the same version as in the Github project, version 1.0.0 preview, not the preview.1 version). Then I got a message about upgrading native backend, which required a restart of the editor. Clicked yes and the editor closed.

And then my project wouldn't open anymore. Unity 2019.2.6 starts, I get a message Compiling Assembly Definition Files scripts and then the editor crashes.
I tried restarting the editor and then restarting the PC, no effect. Tried removing the inputsystem line from the manifest.json in the Packages folder, but that also made no difference.
Decided to go all the way back and delete the _StandardAssets folder and the cinemachine line from the manifest. Now I could open the project again, thankfully.

Tried to do it in a different order, first import Cinemachine, but already at that step the editor crashed again. After I removed the cinemachine line again from the manifest and reopened the project it started recompiling pretty much everything!

I'm not sure if this is related to SAC or InputSystem or Cinemachine, but something is causing the editor to crash.