I've recently updated to Ubuntu 18.04 and have encountered issues with Vulkan, preventing me from using the HD render pipeline. The issue presented itself with a black screen for a few seconds once Unity loads a scene, followed by being logged out of my window manager (tested in awesomewm + the default gnome), so it seems the x session crashes. I'm posting this to share the solution in case anybody else is encountering this, and I haven't seen it mentioned here. The problem is actually not with Unity, but GDM, you can find more details about it here: https://bugs.launchpad.net/nvidia-drivers-ubuntu/+bug/1800465 A solution is to curiously run "sudo vulkaninfo" first, as there seems to be a vulkan permission issue. Once per session is enough. Ubuntu 19.10 is also affected and it works there as well. Hope it helps somebody.