@KillerSmath @raven-worx Thanks. I will try it and post the result later. I think it's a non-trivial task.

The solution was to set the text browsers setTextInteractionFlags() to (textInteractionFlags() | Qt::LinksAccessibleByMouse).
In my case:

textBrowserReadConversation->setTextInteractionFlags(textBrowserReadConversation->textInteractionFlags() | Qt::LinksAccessibleByMouse | Qt::LinksAccessibleByKeyboard);

I found the solution here:

https://forum.qt.io/topic/70075/qtextbrowser-anchorclicked-not-emitted/2

But I'll leave the topic, because it was hard for me to find it through google or the search engine on this forum.

Setting read only to false switches interaction flags from Qt::TextBrowserInteraction to Qt::TextEditorInteraction which disables interactive links.
To enable them back set the Qt::LinksAccessibleByMouse flag:

setOpenLinks(false); setOpenExternalLinks(false); setReadOnly(false); setTextInteractionFlags(textInteractionFlags() | Qt::LinksAccessibleByMouse);

@mrjj As you said this isn't beginner stuff, have tried but can't get it to work properly so I'll leave it for now and return to it after some while. Thank you so much, really appreciate all the help!

I encountered the same issue, but since QtAssistant displays images without telling it where to find them, how does it manage to find them? It has to be somewhere in the qch file, right?

@SGaist Thank you !! It's ok now. I missed viewport...

I suggest to have a look to Scribe Framework.