Map export without materials and looks weird!

I have a map ( for gfx) but when i try to export it into blender, it has no textures and looks like this

I have been trying to fix this for 2 days straight, i have looked through countless dev forum posts.

I found a solution for the strange looking map, it is a property called “Show Blackface” that is enabled with every mesh and because there are so many meshes, it would take too long for me to disable the property for every mesh.

I am fairly new to blender, so i just want to know if there is a way i can simply import and export maps with no complications.
I did see a creation by maplestick but found it too complicating and no tutorials for it.

Any help or feedback is appreciated!

Your face orientations are wrong. If you want to do it the quick (but less efficient) way, you can turn on double sided.

All meshes are double sided, i did try that unfortunately.