Not always reproducible, but reproducible enough.This is happening on the latest promoted build with all delegate related commits as of 1/12/2015. My crash reporter crashes for this build, and I haven’t had time to look into the logs as to why this is happening exactly, but here are the repro steps.
- Drag any widget that has an assignable event delegate into the canvas of another UMG widget
- Name that widget anything, such as BackButton
- Assign an event to that widget and connect it to something. Doesn’t matter what.
- Place a reference of that widget in the blueprint graph somewhere and connect it to something. Doesn’t matter what.
- Delete that widget
- Ensure event and reference nodes are still present.
- Create a new widget of the same type (unsure if type matters)
- Rename new widget to match name in step 2, such as BackButton
- Observe hard crash.
Video evidence of an unrelated missing widget after a move + undo and this bug here at UE4 UMGEx Livestream Demo (Way Longer Than It Needs To Be) - YouTube starting at 1 hour and 3 minutes.