4.20.1 - Static Mesh Editing Changes not saved

When I make edits to a static mesh (migrated from an earlier version of Unreal) they aren’t persisted when I reload the project, even after saving everything.

There’s nothing in the log indicating anything odd other than lots of:


LogEditableMesh: Verbose: DeletePolygons returned
LogEditableMesh: Verbose: DeletePolygons: [45236]
LogEditableMesh: Verbose: DeleteVertexInstances: [135708, 135709, 135710]
LogEditableMesh: Verbose: DeleteVertexInstances returned
LogEditableMesh: Verbose: DeleteEdges: [67864, 67862, 67863] true
LogEditableMesh: Verbose: DeleteOrphanVertices: [22557, 22561, 22559]
LogEditableMesh: Verbose: DeleteOrphanVertices returned
LogEditableMesh: Verbose: DeleteEdges returned
LogEditableMesh: Verbose: DeletePolygons returned
LogEditableMesh: Verbose: DeletePolygons: [45223]
LogEditableMesh: Verbose: DeleteVertexInstances: [135669, 135670, 135671]
LogEditableMesh: Verbose: DeleteVertexInstances returned
LogEditableMesh: Verbose: DeleteEdges: [67824, 67841, 67842] true
LogEditableMesh: Verbose: DeleteOrphanVertices: [22550, 22555, 22549]
LogEditableMesh: Verbose: DeleteOrphanVertices returned
LogEditableMesh: Verbose: DeleteEdges returned
LogEditableMesh: Verbose: DeletePolygons returned

Edit: I managed to get the changes to persist by toggling “Compute Normals” for LOD0 (the only one for this mesh) and hitting build.
Edit2: Forcing an LOD rebuild worked once but now either causes a crash or reverts all the edits.

It sounds like you are hitting a known issue - Unreal Engine Issues and Bug Tracker (UE-61612)

It is fixed in the next upcoming update, which should be released soon.

Great, thanks Stephen! I also found that the keyboard shortcut for Delete in edit mode doesn’t working, but that might be a peculiarity of my setup.
Being able to box select elements would also be very useful.