UE 4.18.3
Steps:
- Import an FBX mesh, use import settings such as Z translation=-4.0 and uniform scaling=2.0. In my case I used a small mesh and the SmallProp LOD settings at import time
- Create a Grass Type and associate this mesh to it
- Populate some grass on your level with this grass type
- open the Mesh Editor for the imported mesh, go to the Import Settings section and change import settings (like change the Z translation and scaling to different values).
- Use menu item Reimport mesh from the Asset menu of the Mesh Editor
- Observe mesh changing aspect in the level populated with the grass type
- Repeat the operation from step 4. of this description a number of times like 5 times or more. If it helps you can also change the scaling in the grass type alternatively, this may help reproduce the problem, and also save the new mes in the Mesh editor from time to time. After a while the problem should show up.
Expected result: each reimport with new import settings would be properly taken into account, the level view will be updated with the new version of the mesh after each reimport no matter how many times we perform the operation.
Actual result: after a few reimports (should happen after 3 or 4 reimports) with different import settings, the mesh takes back its original shape (i.e. no scaling), and potentially other import attributes are reset.
Reproducibility: always on the few meshes I was testing with.
Workaround: restart UE
But I forgot link it to this answerhub thread, and after submission I could not edit it anymore.