Indigo rendering transparency solid black?

Ok, so I tried 2 materials from the Indigo material database, (milk glass and frosted tinted green glass,) and they both turned the scene completely black when rendered except for a few white pixels where my object should be. The object is a candle holder modeled from an extruded circle. When I tried making my own material, only the candle holder is turned black. I have tried recalculating normals outside, but with no success. I’ve tried many suggestions posted on other websites, but none have worked. Why is it doing this?