i tried both the quick fix on a launcher version, and the source edit on the github version, both still have the crash.
it happens when i change too many material slots too quickly in the editor. it doesn’t seem to crash if i edit the materials while the viewport is set to wireframe, and it doesn’t crash if i edit materials through blueprint code; i can swap between random materials as much as i want, on tick, without any problems.
its editing several material slots, in quick succession, in the details panel, that causes the crash.
on 4.13, it works perfectly, i can edit materials without any problem, and on 4.14 and 4.14.1, it causes a crash almost every time i edit a few material slots.