Create about 50~70 blueprints(some are inherited) that have references of FirstPersonCharacter in their bp.
Make changes to FPSChar bp, press compile.
There’ll be massive ‘Files need check-out’ messages pop out, press ctrl+s to save FPSChar bp while they poping
out.
Crash.
EDIT: crash can be prevented by turning off prompt message.
It’s under Edit → Editor preferences → Loading & Saving → Source Control → Prompt for Checkout on Asset Modification, uncheck this and messages are gone.
Thanks for report! This is a known issue for which we have a fix in place for 4.9 that should guard against this (UE-16842). It hasn’t been integrated into 4.9 Preview 1, but should be in a future preview build. I’ll post here when I have some more information on when that will be, and ask you to try again without prompt message turned off. Thanks!