Slicing a stl file

Supermarine Spitfire mark 5b
When slicing this spitfire
I get this
https://www.reddit.com/r/3Dprinting/comments/ddqfoj/slicing_a_stl_file_if_a_spitfire_and_this_happens/?utm_source=share&utm_medium=ios_app&utm_name=iossmf
My guess is the wall is to thin and when I'm scaling it to fit my printer it is none existing wall.
Can any one help me ?
I tried to make the wall thickness but can't get it to work in inventor 2018