Non-english characters in biblatex fail compilation with xelatex/lualatex

Question

I'm trying to compile a document using either XeLaTeX/LuaLateX and biblatex/biber, but I'm having trouble with a bibliographic entry that contains non-english characters. My MWE is:

% -*- program: xelatex -*-
\documentclass[12pt,twoside,headings=big,open=right]{scrreprt}
\usepackage{scrhack,graphicx,subcaption,nomencl,setspace,fontspec,csquotes,microtype,xcolor,tocbibind,xspace,floatrow}
\defaultfontfeatures{Ligatures=TeX}

\usepackage[a4paper,width=150mm,top=25mm,bottom=25mm,bindingoffset=6mm]{geometry}
\usepackage[british]{babel}

\usepackage[style=authoryear-comp, punctfont, sorting=ynt, eprint=false, giveninits=true, uniquename=init, doi=false, url=false, isbn=false, backend=biber, maxbibnames=99, maxcitenames=2, uniquelist=false, backref=true]{biblatex}
\addbibresource{library.bib}

\setmainfont{Minion Pro}
\setsansfont{Myriad Pro}

\begin{document}
\autocite{Cetinkayadonmez1999}
\autocite{Imhoff1984}
\printbibliography
\end{document}

And my .bib file is:

@article{Cetinkayadonmez1999,
abstract = {Abstract},
author = {{{\c{C}}eti̇nkaya D{\"{o}}nmez}, G{\"{o}}n{\"{u}}l and {\"{O}}zt{\"{u}}rk, Ayten and {\c{C}}akmak{\c{c}}i, L{\"{u}}tf{\"{u}}},
journal = {Turkish Journal of Biology},
pages = {457--563},
title = {{Properties of the Rhodopseudomonas palustris Strains Isolated From an Alkaline Lake in Turkey | Growth Medium | Bacteria}},
volume = {23},
year = {1999}
}
@article{Imhoff1984,
abstract = {Abstract},
author = {Imhoff, J. F. and Truper, H. G. and Pfennig, N.},
doi = {10.1099/00207713-34-3-340},
issn = {0020-7713},
journal = {International Journal of Systematic Bacteriology},
month = {jul},
number = {3},
pages = {340--343},
title = {{Rearrangement of the Species and Genera of the Phototrophic "Purple Nonsulfur Bacteria"}},
volume = {34},
year = {1984}
}

The 'Imhoff1984' citation works perfectly, if I comment out the 'Cetinkayadonmez1999' citation.

I read this question, and this question; and tried changing the author line from:

author = {{{\c{C}}eti̇nkaya D{\"{o}}nmez}, G{\"{o}}n{\"{u}}l and {\"{O}}zt{\"{u}}rk, Ayten and {\c{C}}akmak{\c{c}}i, L{\"{u}}tf{\"{u}}},

to:

author = {{\cC}etinkaya D{\"o}nmez, G{\"o}n{\"u}l and {\"O}zt{\"u}rk, Ayten and {\cC}akmak{\cc}i, L{\"u}tf{\"u}},

But this hasn't helped.

I've tried compiling with both LuaLaTeX and XeLaTeX, but neither work with the 'Cetinkayadonmez1999' citation (they both work with just the other citation).

The .bib file is automatically generated by Mendeley, so if it's possible to find a solution that doesn't involve manually fixing every entry, that would be wonderful (my full file has hundreds of entries).

I'm not very accomplished at interpreting .log files, but I'm guessing that the relevant section is:

Package biblatex Info: XeTeX detected.
(biblatex)             Assuming input encoding 'utf8'.
Package biblatex Info: Automatic encoding selection.
(biblatex)             Assuming data encoding 'utf8'.
\openout4 = `main.bcf'.

Package biblatex Info: Trying to load bibliographic data...
Package biblatex Info: ... file 'main.bbl' found.


/MWE2/main.bbl)
Package biblatex Info: Reference section=0 on input line 15.
Package biblatex Info: Reference segment=0 on input line 15.
! Undefined control sequence.
\namepartfamily ->{\cC 
                       }etinkaya\bibnamedelima D{ö}nmez
l.16 \autocite{Cetinkayadonmez1999}

The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

[1

] [2


]
Package microtype Info: Loading generic protrusion settings for font family
(microtype)             `MyriadPro' (encoding: TU).
(microtype)             For optimal results, create family-specific settings.
(microtype)             See the microtype manual for details.
! Undefined control sequence.
\namepartfamily ->{\cC 
                       }etinkaya\bibnamedelima D{ö}nmez
l.19 \end
         {document}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

! Undefined control sequence.
\namepartfamily ->{\cC 
                       }akmak{\cc }i
l.19 \end
         {document}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

! Undefined control sequence.
\namepartfamily ->{\cC }akmak{\cc 
                                  }i
l.19 \end
         {document}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

[3]

/MWE2/main.aux)
Package logreq Info: Writing requests to 'main.run.xml'.
\openout1 = `main.run.xml'.

 )

Answer 1

The error is in

author = {{{\c{C}}eti̇nkaya D{\"{o}}nmez}, G{\"{o}}n{\"{u}}l and {\"{O}}zt{\"{u}}rk, Ayten and {\c{C}}akmak{\c{c}}i, L{\"{u}}tf{\"{u}}},

and precisely in the additional braces around the double family name.

If you change this into

author = {{\c{C}}etinkaya D{\"{o}}nmez, G{\"{o}}n{\"{u}}l and {\"{O}}zt{\"{u}}rk, Ayten and {\c{C}}akmak{\c{c}}i, L{\"{u}}tf{\"{u}}},

you'll have no problems (also i̇ should probably be i).

On the other hand, you can safely type in the names in the normal way they're written

author = {Çetinkaya Dönmez, Gönül and Öztürk, Ayten and Çakmakçi, Lütfü},

Unfortunately, Mendeley is known to do strange things.