[mgrimace]

Originally Posted by JSWolf

Have you loaded the eBook in the editor to have a look at the CSS? It could be that the font is not embedded but if on your system. If that's the case, then viewing it in the viewer would work because if you have the font, all you need is the font-family line in CSS to use it. But on Kobo, it's not there and not embedded so it won't work.

You could post the relevant HTML/CSS code so we can see what's going on.

Thank you, it looks like that might be the case.
Yes, in the editor:
- the 'bug' icon states: unexpected missing generic font family at stylesheet.css (line: 38 column: 17)
- selecting 'Tools: embed referenced fonts', gives an error: 'no embeddable fonts found'

CSS:

.calibre {
    display: block;
    font-size: 0.58333em;
    padding: 0;
    margin: 0 5pt
    }
.calibre1 {
    display: block;
    height: 770;
    overflow: hidden;
    position: relative;
    width: 600;
    padding: 0;
    margin: 0
    }
.calibre2 {
    letter-spacing: -1px;
    line-height: 1.2
    }
.calibre3 {
    letter-spacing: 1px;
    line-height: 1.2
    }
.calibre4 {
    letter-spacing: 2px;
    line-height: 1.2
    }
.calibre5 {
    letter-spacing: -2px;
    line-height: 1.2
    }
.hlink {
    color: inherit;
    text-decoration: none
    }
.justify {
    color: #211d1e;
    font-family: oppjfiltckennerleyproitalic;
    font-size: 1.28571em;
    font-variant-ligatures: none
    }
.justify1 {
    color: #211d1e;
    font-family: oppjfhltckennerleypro;
    font-size: 1.28571em;
    font-variant-ligatures: none
    }
.justify2 {
    color: #211d1e;
    font-family: oppjfhltckennerleypro;
    font-size: 1.71429em;
    font-variant-ligatures: none
    }
.justify3 {
    color: transparent;
    font-family: oppjfhltckennerleypro;
    font-size: 1em;
    font-variant-ligatures: none
    }
.justify4 {
    color: #211d1e;
    font-family: oppjfhltckennerleypro;
    font-size: 1.71429em;
    font-variant-ligatures: none;
    white-space: nowrap
    }
.lpage {
    background-image: url(images/00003.jpeg);
    background-repeat: no-repeat;
    background-size: 600px 770px;
    display: block;
    height: 770px;
    position: absolute;
    width: 600px;
    padding: 0;
    margin: 0
    }
.lpage1 {
    background-image: url(images/00004.jpeg);
    background-repeat: no-repeat;
    background-size: 600px 770px;
    display: block;
    height: 770px;
    position: absolute;
    width: 600px;
    padding: 0;
    margin: 0
    }

Then, it just continues page2, 3 and so on so I didn't copy/paste that. FWIW I don't understand CSS at all and I'm not sure what's important here. The Line error points to the item `oppjfiltckennerleyproitalic`