Resource is not present in the OPF error. Use our trouble shooting guide to decipher e-book errors in SIGIL.
Create Logical TOC, Set Meta Data in SIGIL
Two important items add functionality to your ebook — The Meta editor, describes the cover, toc.ncx, name of book, author, etc and the TOC Editor, which adds a logical table of contents to your ebook.
Ebook Linkable Table of Contents (TOC)
Creating a Linkable Table of Contents is a necessary item in every ebook. With our pre-formatted Formatting Template, it is easy to modify the toc to fit your ebook.