slide blank in slide pane, displays ok in main window + show

I’m using Impress in Linux.
After converting a multi-slide PPT presentation (and correcting dissimilar font issues) for use in Impress, all was well. All slides displayed properly in slide pane, main window, and slide show.

After an accidental hand motion, one of the slides, in the slide pane, shows as background color only. It displays properly in other windows and modes. This slide has background color, overlaid with a .jpg picture, a few text boxes, and an arrow. Some of the text boxes and arrow have simple animation (appear on click). (All other slides show properly in slide pane. Most have similar layers and animation.) I think the text boxes and arrow may be present, but they are same color as slide background. The issue seems to be that the .jpg picture, which covers most of the slide area, disappears on the slide pane.

If I bring the .jpg picture forward, and then return it to its proper layer, the slide in the slide pane shows properly. I saved the file in that condition (.odp file). But on opening it again, the issue remains.

Thank you in advance, for your suggestions!

Well… I guess everybody else was stumped, too.

In any case, after update to LO 6.1.5, this issue seems to be resolved.