Imorting and exporting fbx from 3d max

I received a model of a certain area including buildings (done using a quadocopter)
With textures and FBX file. I add (in 3d max) more elements
And buildings with textures’ so far everything looks good in Max’s viewport.
The problem is when I export from the max to the fbx file then the model I got comes out with overexposure while the models I added in the max come out dark. It seems to me that the problem is in gamma. Is there a solution to this?