render Massive geo shader with Mental Ray Standalone

[sean]

I runned simulation and ouput .mi file in Massive.
And I tried to render Massive Geo Shader in that .mi file with Mental ray Standalone.
I linked "massive_mray" explicitly;
link "./massive-4.1.5/bin/massive_mray.so"
$include "./massive-4.1.5/shaders/mentalray/include/massive_mray.mi"

but I got the following error;
SCEN 0.2 error: scene preprocess control: null root group tag

I attached two verbose version log files.

Do you have any idea about this error?