[juanferna]

I have this problem. But I dont think it is a recipe related problem because if I rename the file (i.e., from file1.epub to file2.epub) the calibre-viewer works properly (al least for the problematic article, it could fail for others articles).
Using the Inspector (CTRL+I), I have realized that, for the problematic article, the navigation bar looks like:
...
<div class="calibre_navbar">
| <a href="../article_22/index_u146.html">Next</a>

| <a href="javascript:void(0)" data-qkhw5mephqnk3z8xyjxwfc="{&quot;name&quot;: &quot;feed_0/index_u231.html&quot;, &quot;frag&quot;: &quot;article_21&quot;} ...

But for file2.epub (viewer working correctly), the navigation bar is:
...
<div class="calibre_navbar">
| <a href="javascript:void(0)" data-7fzo7bdftcnicvpkgwp84f="{&quot;name&quot;: &quot;feed_0/article_22/index_u146.html&quot;, &quot;frag&quot;: &quot;&quot;}">Next</a>

| <a href="javascript:void(0)" data-7fzo7bdftcnicvpkgwp84f="{&quot;name&quot;: &quot;feed_0/index_u231.html&quot;, &quot;frag&quot;: &quot;article_21&quot;} ...