[Scene 3D] [FBX] : Mesh normals are invalid (some values are null)

[Gigo]

Hello! I am looking for help with a problem that I am having with Substance painter's FBX import.
When exporting a mesh from Maya 2018LT to Substance Painter  2018.1.1 it's giving me the "[Scene 3D] [FBX] : Mesh normals are invalid (some values are null) and will be recomputed" and then procedes to smooth some edges that I have set to "hard" in Maya.

This is what substance is doing:



This is what it loks like in maya:



And even UE4 has no problems displaying the correct normals:



I have tried to export from maya with the next combination of options and all of them weild the same result. With the addition that the Tangents and Binormals option, when checked, creates another error:



Please help!

PS: the log file here is from when none of the options above is checked.

[Gigo]

Don-t bother answering. I have solved this. I had a non mainfold edge which maya did not care to show me when using the cleanup tool... SO this is not a Substance problem but a maya one.... 

[Rawbdiel]

Thanks for posting your solution. I had a problem before and cleanup did the same thing. It happened again today and merged any overlapping vertices, re imported, fixed.

[V Ramanauskas]

One more thing. If you are using blender and you import mesh from other 3d application and do small changes. Make sure you "Clean Custom Split Normals Data" at Object Data Properties -> Geometry Data. Bloody thing was giving me errors, I was looking for some incorrect mesh or normals, but it turned out to be a simple solution. Wasted time, but at least now I will know in the future