Layout continues to crash on launch in High Sierra beta 5. One interesting thing is that the crash happens before the stage where a preferences file is written.
I tried opening the executable file, Layout.app/Contents/MacOS/Layout, that was informative! The file:
is not being found, and if you go there you’ll see it doesn’t exist. There are three other files that all link to the same Ruby framework, so I tried duplicating one and renaming it as libruby.2.0.0.dylib. Unfortunately that didn’t fool Layout into working!
Reading reports of the same problem in other applications showed up this Apple article, that might be relevant: