I know that 3D widgets are experimental but when adding one to a BP and then trying to move or rotate that BP actor instantly crashes the editor and in my humble opinion, that should not be the case
Repro:
Open FPS examlpe map
create an Actor-derrived BP and an UMG widget with a button dragged in.
Add widget component to BP, compile and save
place actor in scene and try to move it (sometimes it is not instantly crashing though…)
I was able to reproduce this issue on our end. I have written up a report (UE-25635) and I have submitted it to the developers for further consideration. I will provide updates with any pertinent information as it becomes available. Thank you for your information and time.