Substance Designer MDL to Vray

I’m attempting to create MDLs in Substance Designer, export them, and render in vray for Maya. My MDLs always error out when I attempt to render them but the vMaterials render fine in vray.
I’m just trying to track down where the issue might be, is there an incompatibility with the current Designer export version with vray? Or neither are compatible with the latest MDL dependencies? I’m also asking in the Designer and Vray Forums and I’m asking here just in case anyone has had a similar issue. I realize it’s like not anything on the MDL side, there just isn’t much information about this around so casting nets where I can.

It is possible that vRay is not supporting the MDL version that SUbstance Designer is writing to disk. So if you are creating an MDL file with the latest version of Substance Designer and you try to load it with a vRay version that only supports a lower version of MDL you will have errors.
Check your .mdl file exported from Designer, what MDL version does it report on the top of the file?
Compare that number with the MDL version vRay supports. If this number is higher than what vRay supports, then you need to create/export your MDLs with an older version of Designer.