Importing FBX animation crashes at 75% UE4.9.2

Hello all,
so im fairly new to UE in general and im just trying to set up a first character that is moving around inside the engine.
Im using a curstom self made skeleton which is fairly complex to be honest. The thing is that the skeletal mesh imported just fine the first time with all the joints and weights. (349 joints, 49 separate geos, ~75k verts).
But if I try to then import an animation using the same skeleton UE simply hangs at 75%, then crashes after a minute.

I then tried simplyfying the skeleton a bit (by removing non-skinned end joints) and then even the skeletalMesh caused a crash when importing the updated version.
Upon crash it returned a huge stack trace feedback which might be useful to someone with access and understanding to the files involved. I attached a .zip with the diagnostics file and the .fbx which contains the sole skeleton with a super simple animation (skeleton that was working when imported in an fbx that contained the meshes… now also causes a crash if imported as simple animated skeleton - even into a new emtpy project).

https://dl.dropboxusercontent.com/u/25584030/DiagnosticsAndFBXfile.zip

My guess would be the number of joints for the whole skeleton still exceeds 255. But I thought that limit was only for joints within one skinCluster. But since the actual skeletalMesh loaded fine and I could view and tweak its skeleton with skinning and everything in the persona view im not so sure no more…

Nevermind, I figured it out myself… cant believe it was something so trivial.
Basically im working on maya 2015 and 2016 simultaneously since both have some benefits for me performance and compatibility wise.
The first skeletalMesh that worked I exported in 2015 so the fbx format was the correct one. Then for some reason I switched to 2016 for the animation baking process. Obviously by default it exports with a 2016 signature which after reading through the docs I realized UE isnt compatible with (yet, I hope).
SO I changed that in the export settings and all works like a charm now…