Not blaming LiveCode for this issue! And it isn't really an "issue" as I was just curious how LC would behave in such a new environment. I expect other 3rd party apps will have just as much fun in High Sierra until everything gets sorted out.
"Hey y'all! Watch this!" may be fine for YouTube fails but certainly is not a reasonable behavior when involving LiveCode and beta operating systems, right?

Perhaps it's the APFS filesystem? Who knows? I'm going to nuke and re-pave the SSD now.
Rumple
*Edit: Actually crashes whether I click the "OK" or "Cancel" button in the color picker.