Problems importing .fbx file, UE4 editor crashes

Hello
i am trying to import a weapon 3d fbx model, that I downloaded for free from CGTrader. This is the model I downloaded : https://www.cgtrader.com/free-3d-models/military/gun/colt-m4a1-sopmod-overkill

it is .obj, so I imported it in Clara.io, and added it a root bone so that I can use it in my FPS game. This is the model after my edit: https://clara.io/view/469ef5b1-5c7b-4f70-adf6-0b546b9d39b9

The problem is, if I import the original model, in .obj format, the import goes well, but the weapon comes in 3-4 parts, so I can’t use it. That’s why I tried to make it a fbx skelthal mesh, but when I try to import the fbx file from Clara.io, the UE4 Editor freezes at 75%, and becomes unresponsive.It almost uses my entire Ram 3.400 MB of RAM ( I have 4.000 MB RAM), and the PC is not longer responding. I tried to convert it using Autodesk converter, but I have the same result.
Can anyone tell me how can I convert it to uasset online ( because I think my PC is not powerful enough), or, is there any way to import the original file in one single mesh?
If anyone is very kind, can he/she import the fbx model into his/her UE4 and send me the .uasset file please?

A few things
First–if your system only has 4GB of RAM then you don’t meet the minimum requirements to run UE4, so that could be part of the issue.
Another thing is that the model is not designed for games, it’s a high poly model and needs to be optimized before using in a game engine.
Last thing is that you’ll need to use a good FBX exporter, I would try importing to Blender and then follow a guide on how to export FBX files from Blender to UE4 properly.

Thank you sir, I will try to use Blender.
Even though I only have 4Gb of Ram, except for the .fbx import part, UE 4.15 is running pretty smooth, without any freezes while doing other tasks.
Thank you once again.

if that model has NOT been optimized and its high poly, How can this be game ready? I just took a look at the wireframe mode, there’s too many polys on that model…

But since you only have got 4gb of ram which is not even the miniminal requirement of Unreal Engine and also
on top of that windows is using about half of that along with other tasks you are running, Your best bet would be to either upgrade to more memory or add in level streaming to your map so it reduces the number of things the engine
has to draw on the screen and reduce the number of polys on that model.

I have 16 gb of ram, but that’s the minimal requirement, you’re supposed to have up to 32 gb.