@C-novice...Whenever you get xmlns declaration errors all over the place in your html code, this usually indicates that there is an xmlns attribute declaration missing from within the <html> tag in the headers at the top of your html files.
In Book View you said your ebook text looks like this:
'. . .he had always done.</span></p> <p class="subsq"><span xmlns=beyond to the woods. </span><span xmlns=
My wild guess is that the above code in Code View will look like something like this due to the missing/incorrect xmlns declaration in the <html> tag at the top of the file:
'. . .he had always done.</span></p> <p class="subsq"><span xmlns="">beyond to the woods. </span><span xmlns=""
Can you please copy and paste the <html> tag line from any epub xhtml file in your next post so we can see it? The <html> tag line occurs directly after the <!DOCTYPE> line in at the top of your html files. As a reference for you, the headers at the top of your epub 3 xhtml files should all start like this:
You also have a bunch of errors in your opf and toc.ncx file. It would also really help tremendously if you posted the code from the <manifest> section in the content.opf file and also posted the code from the toc.ncx file from your epub into your next post. Your toc.ncx might be using a nav map that uses <navpoint> tags which is only relevant for epub 2 format. For epub 3 you should be using a nav map that uses an ordered list within <nav> tags only. This is another wild guess on my part since I really don't know that much about epub 3 format.
A proper epub 3 toc.ncx looks something like this:
Did you use another application to convert your doc to Epub 3 ? If so, what is the name of the app ? Or did you code your epub manually ?