Objects have inverted lights!

[Oski29]

Hi! For quite some time I have a problem with my 3D models
Sometimes when I import these models into Unreal Engine… they don’t seem to work.
Light are inverted inside. I tried flipping the UVs, using two-sided textures and nothing seems to work.
Model will only have normal colors when a light source is inside it.

Can some please help me? Usually I would just recreate the model but it’s so time consuming!

[glitchered]

check the vertex normals and make sure the normal maps convert into proper unreal tangent space.

[Oski29]

I found the reason as to why this issue occurred.
It actually wasn’t anything to do with the vertex normals but with the transform of the object in Blender.
Thanks for help anyway!