I’m hoping this will help others.
I had the same error when trying to cook the content, I have 4 lighting scenarios in my archviz project and they were all above 3.6GB!
The problem for was not the lightmaps being too large or too many it was actually the reflection spheres. I had over 20 of them and I had the resolution for sphere capture set at 1024. After erasing most of them and changing their resolution to 512 all my lighting scenarios went from 3.6GB to just 0.8GB!! well under the 2GB limit.
So whoever encounters this problem please check your options for sphere capture and see if you can remove some from your scene, this will help greatly! It’s a quick fix as well, you don’t have to bake anything just remove what you can and then press SAVE ALL and check the new size of the BuiltData in your content folder.