I created a project in 5.0, created a number of levels, updated to 5.0.3 and imported landscape-heightmaps that I created in Gaea. One of them was altered directly (flattening a part down so it could fit my scene) and I painted it using a number of materials, partly automatic (following one of the courses on Internet) and that works file.
Next I migrated the project to 5.1, UE offered to open a copy, which I did. Next, I opened this level but now I get the message “Landscape: physical textures need to be rebuild” when the level is opened but I can get on. However, when I choose to rebuild all, which gave me quite a number of warnings.:
Map Check: “StaticMeshActor_(number) Static mesh actor has NULL staticMesh property”. As it turns out, these are the ‘squares’ of the landscape that I edited (flattened to below existing scene) - by deleting the actor, I got a hole in my landscape.
Lifghting results: quite a lot of the assets I used to create the walls of my scene have a warning: “(assetname) Object has wrapping UV’s” and are now missing from the scene.
Closed project without saving. Same issues returned on opening again.