Adding Video Clip to Image Bric

I’m having trouble putting a short iMovie mp4 video into an Image Bric that has several other still images. I select Lightbox interaction>Video, and try to drag/drop the video from the Asset Manager. But there is no little green plus sign, and the only video that plays is the stock seashore clip. I have gotten it to work before, but not after a lot of effort and still not understanding what I did correctly in those cases.

Forgot to mention, I am using 6.3.0 and OS 15.6.1

I’ll take a look.

It works as expected if there is only a single image bric in the row/column, but not if there are multiple columns with jpgs in the row.