I have noticed that with the 1.31.0.12 release and PBR enabled, any object with a face having a texture containing an alpha channel is completely invisible. This can be demonstrated by rezzing a cube and then setting its texture to the Library's White - Transparent (semi-opaque). In version, 1.31.0.11, the cube will render as expected as a 'ghostly' or 'smokey' partially see-through cube. In 1.31.0.12, it is completely invisible. The behavior shows up with shadows enabled, either sun & moon or all.
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