UE4 Error : Failed To Merge Bones

Hello everyone,i have a big problem here.

In Maya3D 2016 i created a simple bridge model with its own animation.
The problem is that when i try to import the model into UE4 i get this error :

92959-capture.jpg

When i click yes the model is imported correctly but the animation is really messed up and i really don’t know what the problem might be.
At first i used only contraints on Maya,but then even with joints i get the same error.
[Here][2] are the .ma project for Maya3D and the exported .fbx model if anyone can see it and help me it would be very appreciated.

Thanks and have a good day!

what skeleton are you assigning it when you import your mesh? Or are you generating a new one?

The mesh needs to be skinned to the joints. Are they?