if you look around on the forum, you’ll find dozens of similar threads from the last month, mac os sonoma, when changing material, makes sketchup crash.
here, I searched for you
and if you check the last few posts, you’ll see that sonoma 14.4 fixed the crash issue.
now, if you’re still crashing, it means you have another material related problem.
you mention bug splats in the title, do you send them ? fill in the infos, and send the splats ?
If so, do you have the bugsplat numbers at hand ? it’ll make it easier for the devs to find them.
keep in mind it’s sunday, 3-4 am right now at sketchup headquarters. and also, weekend.