Light Map Resolution is set to a small value (4 or 8), it will build normally.
1.Download Attachment file.
2.Create New Project.
3.Move ST_Sphere_LMIdx4_01a.uasset included in attached file to project.
4.Set unique UV for Static Mesh's UV Channel 4. (ref 327164-dix4-uv.png)
5.Set the Light Map Coordinate Index to 4.
6.Place static mesh on the level.
7.Start Lighting build/
Ref: after Lighting build.png
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-64615 in the post.