Hello Timos 153,
I have created a test project with starter content.
I used the Minimal_Default map with the table and chairs.
I attached a point light to the table. I then created a folder and called it Folder inside of Content. I found the table inside of the Starter Content area and Moved the table to the “Folder” folder I created. It moved just fine.
A couple of steps I would like for you to do.
1.) Recreate what I have done and see if it still crashes UE4
2.) If not send me the .fbx of your train and I will look to see if it is an issue with the Static Mesh.
3.) Let me know what you find.
Thanks,