When the 'Fracture' button is clicked on a Destructible Mesh made from SM_MatPreviewMesh_02, the editor immediately freezes and stops responding.
1. Open the Example Editor
2. Find a static mesh
3. Right click it and select Create Destructible Mesh
4. Open the DM
5. Under Fracture Settings>Voronoi, change the Cell Site Count to a very high number (like 5000)
6. Hit Fracture Mesh
The fracture process starts, but the editor more or less becomes frozen for a long time
A warning message if you set the Cell Site Count above, say, 1000 that says You are attempting Fracture with a very high Chunk count, this may take a very long time. Would you like to continue? Y or N . With an option to dismiss this message in the future.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-3844 in the post.