这是我的最小示例：
% arara: xelatex
% arara: biber
% arara: xelatex
\documentclass{article}
\usepackage[backend=biber,style=authoryear,sorting=nty]{biblatex}
\addbibresource{mwe.bib}
\begin{document}
Citation\cite{Walco2008}
\printbibliography
\end{document}
mwe.bib文件包含以下内容：
% This file was created with JabRef 2.10.
% Encoding: UTF8
@Book{Walco2008,
Title = {Pain in Children},
Author = {Gary A. Walco and Kenneth R. Goldschneider},
Publisher = {Humana Press},
Year = {2008},
__markedentry = {[ilija.pavlic:6]},
Owner = {ilija.pavlic},
Timestamp = {2014.06.09},
Url = {http://www.amazon.com/Pain-Children-Gary-A-Walco-ebook/dp/B008BB7LUW%3FSubscriptionId%3D0JYN1NVW651KCA56C102%26tag%3Dtechkie-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D165953%26creativeASIN%3DB008BB7LUW}
}
当我尝试编译它时，我从 biber 收到以下失败消息：
Running Biber...
Use of uninitialized value $llabel in concatenation (.) or string at Biber.pm line 664.
Use of uninitialized value in string eq at Biber/SortLists.pm line 77.
INFO - This is Biber 1.5
INFO - Logfile is 'mwe.blg'
INFO - Reading 'mwe.bcf'
WARN - Warning: Found biblatex control file version 2.6, expected version 2.3
INFO - Found 1 citekeys in bib section 0
INFO - Processing section 0
INFO - Looking for bibtex format file 'mwe.bib' for section 0
INFO - Decoding LaTeX character macros into UTF-8
INFO - Found BibTeX data source 'mwe.bib'
FAILURE
我需要修复什么才能让这个最小示例引用并打印参考书目？