I am currently doing a very long document in LaTeX (my thesis), and the structure of the document I'm writing the number Appendix fifteen, but as we know in Spanish the number letter fifteen is the ñ, then to compile I get an error, I tried have a minimum document if suddenly is a mistake of the document and I went out the same error. I am using TeX Live 2014

the error is:

```
Extra \ or. ... {\ 'E} index 15} {33} {Appendix.alph1.Alph15}
Something's wrong - Perhaps a missing \ item. ... {\ 'E} index 15} {33} {Appendix.alph1.Alph15}
Missing} inserted. ... {\ 'E} index 15} {33} {Appendix.alph1.Alph15}
Extra \ else. ... {\ 'E} index 15} {33} {Appendix.alph1.Alph15}
Something's wrong - Perhaps a missing \ item. ... {\ 'E} index 15} {33} {Appendix.alph1.Alph15}
Missing} inserted. ... {\ 'E} index 15} {33} {Appendix.alph1.Alph15}

```

and more detail that line is in the `.toc`

```
\ contentsline {chapter} {Ap \ '{e} index \ numberline {\ ~ N} ap \ IeC {\' e} index 15} {33} {Appendix.alph1.Alph15}

```

How do I remove this error because I need to do this appendix, I annex the minimum document also gives me error:

```
\documentclass[10pt,letterpaper,spanish]{book}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{babel}
\usepackage[title, titletoc,page]{appendix}
\usepackage{graphicx}
\usepackage{hyperref}
\begin{document}
\frontmatter
\tableofcontents
\mainmatter
\chapter{capitulo 1}
\appendix
\chapter{apéndice 1}
\chapter{apéndice 2}
\chapter{apéndice 3}
\chapter{apéndice 4}
\chapter{apéndice 5}
\chapter{apéndice 6}
\chapter{apéndice 7}
\chapter{apéndice 8}
\chapter{apéndice 9}
\chapter{apéndice 10}
\chapter{apéndice 11}
\chapter{apéndice 12}
\chapter{apéndice 13}
\chapter{apéndice 14}
\chapter{apéndice 15}
\end{document}

```