Hi, can you try this ?
<NEW-FRAME Center="(0, -.375, 0)" Quat="(0, 0, 1)(90)" ID="F7"/>
<NEW-GROUND Type="Rectangle" DimY=".1" DimZ=".1" FrameID="F7" ID="G7" Set="G7"/>
...
<DELETE What="Physic::GroundT<Rectangle>" ID ="G7" Set="G7"/>
This is just a quick fix (I have not tried it)
Cheers, Damien