"Package inputenc Error" when using biblatex with accented characters

Question

I'm getting errors such as this: Package inputenc Error: Unicode char \u8:ärt not set up for use w and this Package inputenc Error: Unicode char \u8:é\isdot\ifblank not set when trying to compile a bibliography in the below code. There is clearly some sort of an issue with the accented characters. Does anyone know how to resolve?

\documentclass[12pt, a4paper, oneside]{Thesis}\usepackage[]{graphicx}\usepackage[]{color}
%% maxwidth is the original width if it is less than linewidth
%% otherwise use linewidth (to make sure the graphics do not exceed the margin)
\makeatletter
\def\maxwidth{ %
  \ifdim\Gin@nat@width>\linewidth
    \linewidth
  \else
    \Gin@nat@width
  \fi
}
\makeatother

\definecolor{fgcolor}{rgb}{0.345, 0.345, 0.345}
\newcommand{\hlnum}[1]{\textcolor[rgb]{0.686,0.059,0.569}{#1}}%
\newcommand{\hlstr}[1]{\textcolor[rgb]{0.192,0.494,0.8}{#1}}%
\newcommand{\hlcom}[1]{\textcolor[rgb]{0.678,0.584,0.686}{\textit{#1}}}%
\newcommand{\hlopt}[1]{\textcolor[rgb]{0,0,0}{#1}}%
\newcommand{\hlstd}[1]{\textcolor[rgb]{0.345,0.345,0.345}{#1}}%
\newcommand{\hlkwa}[1]{\textcolor[rgb]{0.161,0.373,0.58}{\textbf{#1}}}%
\newcommand{\hlkwb}[1]{\textcolor[rgb]{0.69,0.353,0.396}{#1}}%
\newcommand{\hlkwc}[1]{\textcolor[rgb]{0.333,0.667,0.333}{#1}}%
\newcommand{\hlkwd}[1]{\textcolor[rgb]{0.737,0.353,0.396}{\textbf{#1}}}%

\usepackage{framed}
\makeatletter
\newenvironment{kframe}{%
 \def\at@end@of@kframe{}%
 \ifinner\ifhmode%
  \def\at@end@of@kframe{\end{minipage}}%
  \begin{minipage}{\columnwidth}%
 \fi\fi%
 \def\FrameCommand##1{\hskip\@totalleftmargin \hskip-\fboxsep
 \colorbox{shadecolor}{##1}\hskip-\fboxsep
     % There is no \\@totalrightmargin, so:
     \hskip-\linewidth \hskip-\@totalleftmargin \hskip\columnwidth}%
 \MakeFramed {\advance\hsize-\width
   \@totalleftmargin\z@ \linewidth\hsize
   \@setminipage}}%
 {\par\unskip\endMakeFramed%
 \at@end@of@kframe}
\makeatother

\definecolor{shadecolor}{rgb}{.97, .97, .97}
\definecolor{messagecolor}{rgb}{0, 0, 0}
\definecolor{warningcolor}{rgb}{1, 0, 1}
\definecolor{errorcolor}{rgb}{1, 0, 0}
\newenvironment{knitrout}{}{} % an empty environment to be redefined in TeX

\usepackage{alltt} % Paper size, default font size and one-sided paperR
\usepackage{alltt} % Paper size, default font size and one-sided paperR

\usepackage{nameref}

\usepackage{array}
\usepackage{booktabs}
\usepackage{tabularx}

\usepackage{etex}

\usepackage{lmodern}

\usepackage{caption}
\captionsetup[table]{position=below}

\usepackage{placeins} % to control figure placement with \FloatBarrier

\usepackage{fontspec}
\setmainfont{Lucida Sans}

% biblatex----------------------------------------------------------------------------------------
\usepackage[style=authoryear-comp, maxcitenames=2, maxbibnames=99, uniquelist=false,firstinits=true,sorting=nyt]{biblatex}
\DeclareNameAlias{sortname}{last-first}
\DeclareNameAlias{default}{last-first}

\usepackage{xpatch}

% No dot before number of articles
\xpatchbibmacro{volume+number+eid}{%
  \setunit*{\adddot}%
}{%
}{}{}

% Number of articles in parentheses
\DeclareFieldFormat[article]{number}{\mkbibparens{#1}}

\renewbibmacro{in:}{}

\addbibresource{\jobname.bib}

\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@article{PartDoligez2003,
  title={Gathering public information for habitat selection: prospecting birds cue on parental activity},
  author={P{\"a}rt, Tomas and Doligez, Blandine},
  journal={Proceedings of the Royal Society of London. Series B: Biological Sciences},
  volume={270},
  number={1526},
  pages={1809--1813},
  year={2003},
  publisher={The Royal Society}
}
@article{HacheEtAl2013,
  title={Experimental evidence for an ideal free distribution in a breeding population of a territorial songbird},
  author={Hach{\'e}, Samuel and Villard, Marc-Andr{\'e} and Bayne, Erin M},
  journal={Ecology},
  volume={94},
  number={4},
  pages={861--869},
  year={2013},
  publisher={Eco Soc America}
}
@article{Hilden1965,
  title={Habitat selection in birds: a review},
  author={Hild{\'e}n, O},
  journal={Ann. Zool. Fenn},
  volume={2},
  pages={53--74},
  year={1965}
}


\end{filecontents}

\begin{document}

    \cite{PartDoligez2003}\\\\
    \cite{HacheEtAl2013}\\\\
    \cite{Hilden1965}

\printbibliography

\end{document}

Answer 1

I have no problem compiling, if I declare Lucida Sans Unicode as main font. I suspect Lucida Sans is a type 1 font, requiring font encoding declaration, &c., which might be the source of the problem.

Incidentally, to have nice quotes in your bibliography, load csquotes. Without it, I had hideous fake opening quotes. Also, you may type accented letters in the .bib file: biber understands UTF8.