Error message: Invalid image: cannot identify image file <_io.BytesIO object at 0x000
 

Is the any way to repair this?

Calibre 5.6, win10; epub generated with oxygen 20.1 from docbook source file by ant.
There are two error in total. what can I do to get rid of this. A third error (complaining about an empty image) I could repair by exchanging it in Calibre's book editor. But the other two are resilient, unfortunately.

When I open the ebook the images are there. Very strange.

Kind regards!