Problem after BlueScreen

Yesterday Unity caused a bluescreen, and I lost some work on terrain detail.

Now, when I try to start the build, I get the error:
“Failed setting triangles. Some indices are referencing out of bounds vertices. IndexCount: 3540, VertexCount: 62315
UnityEditor.UnityBuildPostprocessor:OnPostprocessScene()”

And for some reason I’ve a mouse curser offset, I can’t work with the cursor anymore…

If I run the build ignoring the fail, my whole scene is f**ked up with strechted meshes all over the scene.

How can I fix this!? As long as I have this issue, I can’t really test my progress. Otherwise, if I don’t get a solution, some hundred hours of work are gone…

Figured it out.

For anyone else who has this annoying issue:

Try to clear an recalculate all the occlusion and lightmaps.

I just got it by try & error, there is no hint in the console for the correct solution.