Hello , i fixed my same problem .
i have terrain in my scene . if you have terrain in your scene then click terrain and look inspector . go to paint texture(textures) / settings / lighting , find lightmap static . and uncheck lightmap static . save scene and project , build again . this is fixed my problem about file headers .
Don’t do this if you want to use baked lightmaps. Instead, take a look at the lightmap files, they’ll be inside the folder with the same name as your scene, a subfolder in folder that contains your scene.
If you have the same problem I did, you will notice that the lightmap files are uncompressed if you use inspector. (RGBA 32bit) i.e MASSIVE!!!
Override the compression setting with anything other than uncompressed and you’ll see the Header size reduce dramatically. I used the manual lightbaking method. I’m not sure how well this will work with Autogenerated lightmaps.