Black secondary mirror on video

I’m trying to render a video that has a reflection of a mirror, and it appears black! on photo mode it doesn’t happen. what should I do? I’m really sad about it, because I bought d5 render pro just to do this job and now, i’m having this enormous problem! please help!

Hi Jessica,

May I have some screenshots of the issue? which can help us know it better!

Thank you very much