Motion blur

I have rendered animation with velocity channels and now I have problem applaying blur using RSMB in After effects.
Does anyone have experience using it and would like to explain it as simple as posible.
Thanks.

Have u used rpf?
If so, the velocity channel of the rpf file is not compatible with Reelsmart motion blur. However, you still can use the plugin in AE disregarding the velocity channel and it could work great.

I have saved velocity chanell in render elements rollout. (vray 1.49.25)
If its not compatible with rsmb than I dont think I can do motion blur in Aftereffects at all. Without velocity chanell it is the same as 3dsmax image based motion blur and thats crap.
So any other solution here or my client will see no motion blur in animation.
Thank god the camera is very slow so without blur it still looks ok.