How to fix generate lightmap uvs issue?

I’m sure this question was asked before but I can’t find it. I save the.blend and in the fbx importer click generate lightmap uvs. I apply the changes and it loads. Now here’s the problem. It doesn’t stop loading until I reset the computer. This only happens with a higher poly object. Hope there’s something to do so I don’t have to stick to 3000 tri meshes. Thanks for your time.

It usually takes longer for more detailed meshes, but it usually completes at some point. You can always create UV2 in Blender yourself if you think that will be easier workflow.