I've done a successful camera zoom/pan of a scene but want to zoom more than I did so I'm doing the scene again and have run into this problem. Anytime I add a camera to the scene and do the zoom/pan, I get a horizontal line on the scene on one or more of the frames. They show up in the zoomed in view (and in the media file I create) but when I zoom out the view, the line isn't there. Here's the zoomed in view of a frame
Here is the zoomed out view of that frame
When I create a media file and run it, the horizontal line flashes on the screen on that frame.
I've tried it a number of times (from scratch) and sometimes I get one line, sometimes more than one.
Hiding my layers, the line is on the background layer.
Nevermind, I figured it out. I had a solid color rectangle at the bottom (to extend the background in y direction) that apparently, in zooming, separated itself a lines' height from the background for a frame.