Pig of a crash - "Pure virtual function being called while application was running"

That worked for me at least.

Just for reference, I’m in a BP based project (not a single one C++ own class), and the Editor sometimes crashed giving this error when attaching a particular BP of mine to the PlayerStart instance. In other cases, it crashed afterwards when moving around the PlayerStart with the BP as a child, and then press Ctrl+Z.

Besides, I’m using Paper2D and PaperZD for the attached BP.