Images not appearing on pages, white line on cover page, and text not crisp

Question

I'm using this software for the first time and exporting my publication as a flipbook. And I'm having all these issues:

1. Images not appearing on pages (I can see the images in the menu at the bottom)
2. white line on cover page (there's a line where 2 boxes of different colors meet)
3. and text not crisp (it's slightly blurred).

Any helps is sincerely appreciated.

Thank you.

UPDATE: I was able to solve issues 2 and 3 by changing the text to SVG. But, the images are still missing. I have the copyright. They are in the picture frame with the setting fitting the frame proportionally. I don't know what else to do.

Any help is appreciated.

Thank you!