(IN-66726) Enabling APV in URP with Render graph throws errors when ctrl is pressed in scene view.

I just hit this issue myself while working on another Unity bug. I filed a new bug about the problem.

While you wait for a fix, one (slightly annoying) work-around is to simply add the Screen Space Ambient Occlusion Renderer Feature in your URP settings asset (in the Renderer Features section). At least that worked in my case.