what you can do is create a new level. Then create the directional light set to static and build, see how long this takes. Then add one static mesh object, build and see how long this takes. If this doesn’t take too long, add a large number of the meshes in the project, build and see how long that takes. What it sounds like is occurring is the primary level may have a lot of static lights and you are attempting to bake all of that lighting at once, which may take a long time depending on how many lights/meshes, etc. that are in the level.