Hi,
I am working at the moment for company which has a Cinema 4D REL 16 pipeline. I have serious problems to export FBX (2013) models from this software to UE4. The smoothing groups are not recognized. I have to import the Cinema 4D FBX model always to Maya 2014 and save it there again as a FBX file. Then the smooting groups are imported correctly. This is really annoying. Please fix this bug in the next update.
Best regards, Andreas
Hi,
This issue has been addressed in this post: https://answers.unrealengine.com/questions/32686/c4d-smoothing-groups-inconsistent.html
It appears to be an issue on C4D’s end. The assets provided in the linked post had smoothing issues with the FBX when I imported into 3Ds Max. I did not load them in UE4 as that test ruled out UE4 being the issue.
If your exporter has the option you will also want to export as FBX 2014 as this is now the supported version. You can use FBX 2013 but there may be a warning in doing so every time you import an asset. The FBX 2014 export also appears to be the fix for the user in the post.
Let me know how it goes. 
Tim
Hi Tim,
thank you very much for your response. I will try FBX 2014.
Best regards, Andreas
the solution is no use edge breaks in the phong tag!
I tried to disable the edge break option. But I get always an error message that no smoothing groups are found. (FBX 2013 & 2014) I checked the model in UE4: There is no smoothing visible.
I had to abandon UE4 and switch back to unity for exactly the same reason, which is a massive shame. 
Any good working Solution? Same Problem but its May 2015
This works: export model from c4D (I’m using R16) as FBX, open in Maya PLE (free from Autodesk), export from MayaPLE using their FBX exporter, with smoothing groups enabled.
still problems here too