Originally Posted by nrapallo
If you double-click that .html, does it show the ebook in your browser?
If so, then you did convert the ebook and the output is in the same directory that your input file is located in. Otherwise, ensure your output format is '.prc' since this behaviour is also typical of the .html output format.
If not, then the .pdf source file has 'issues' being rendered into images i.e. protected .pdf, encrypted .pdf or corrupt .pdf.
Try it with another .pdf to see if the software works "as advertised"
The html created is fine and images too, but they are in a temporary directory and no .prc is created. With another .pdf it worked fine.