I'm using one of Dex's wrestling freebie props, and it looks fine when it is in the document window (unrendered), but when I try to render it in P5, these black lines and boxes appear over the whole prop, completely ruining the image. This has happened to me a few times with other props as well, and I never did figure out the problem. Any suggestions would be much appreciated.

Above is what the scene looks like in the document window before rendering, and then what it looks like rendered in Firefly with default production settings. Thanks.