This issue has been around for a while - I only just now got around to reporting it. I think I raised it a long time back and it was fixed, but the problem reappeared sometime since.
- 1. Run Floating Preview on an image.
2. Go back into the list in the main window, navigate up to the parent folder it and rename it.
3. Go back to the preview window and try to zoom the image with Ctrl-Scroll Wheel.
4. Image goes away with error: No Preview Available
The typical use case where this arises for me is when I rename the parent folder with information I see in the image, and then go back to the image and happen to zoom to better see other info.