Your comments

I reproduced the problem you have with the logs.
Investigating...
I am not familiar with the way Apple filesystem works, but I suppose you could try to add quotes around the path:

"/Volumes/Macintosh HD/comix"
Also, are you using the web admin page or th desktop interface to configure Ubooquity ?

Yes, you can do that by creating a specific theme and hiding the download button in the CSS.

Once you have generated your new theme (or chosen the theme you want to edit), you have to modify the books.css and comics.css files by hiding the #details_download id.
#details_download {
    visibility: hidden;
}

I did it for the default theme, you can download the modified version here.

Hi,

thanks for the offer, but Ubooquity is closed source software.
Although I am not against the idea of opening it someday, I have no plan to do it so far.

So for now, the only way to customize Ubooquity is through themes. I also plan to make the Javascript part (so mostly the online reader) customizable in the next release.
Hi,
there is no option for that.