Output epub files have a formatting issue, which most reader apps complain about or simply don't open the file. Only Calibre's e-book reader was able to open it. By checking the file, I came up with these issues:
iBooks app stated it as "Opening and ending tag mismatch: link line 0 and head"
Using epub validator tool, I came up with many "Error while parsing file: The element type "link" must be terminated by the matching end-tag" errors.
Apparently, some html tags, particularly "link" tags don't have corresponding closing tags. The only way of fixing the file is using ebook converter tools and converting the file again to epub file, which proves that the book itself isn't damaged, only minor formatting issues prevent it from being a valid epub file.
Output epub files have a formatting issue, which most reader apps complain about or simply don't open the file. Only Calibre's e-book reader was able to open it. By checking the file, I came up with these issues:
Apparently, some html tags, particularly "link" tags don't have corresponding closing tags. The only way of fixing the file is using ebook converter tools and converting the file again to epub file, which proves that the book itself isn't damaged, only minor formatting issues prevent it from being a valid epub file.