Our team is working on a large map filled with a very high number of static meshes (each one of the ~90 building blueprints consist of several modular pieces). Apart from minor lighting issues that were fixed relatively quick the lightmap build worked out quite good. The whole project was saved.
But when we opened up the editor the next time, some of the static meshes that were fine just hours ago have turned completely black. A lighting rebuild fixed the black meshes until we restarted the editor, then the same meshes were black again. Building the light and immediately packaging the project for windows 64bit didn´t solve the issue either, the meshes turned black again.
Here is a picture showing some of the black meshes:
We assume there is a problem in how Unreal stores the lightmaps, but we are not 100% sure. Maybe the reason for the problem is to be found on our side. Either way, any help would be appreciated