A couple things to try if you haven't already:
- Toggle F10 (View/Preview on menu), sometimes the preview window is on a different monitor in multi-monitor setups...or perhaps in a tab on the side window. Toggling brings it to the forefront.
- after double-clicking the image in the Images folder in the Book Browser, the image should appear in the Main window area. I have noticed that it will occasionally be blank until I force it to refresh by moving the scroll wheel a little bit. What kind of image is it (jpg, png, svg) ??
I'm running on a Windows 11 and it seems to work fine.