I am not sure why I cannot copy from the TeXShop console anymore, but here is my problem. This does not seem to be related to my bib file or how I cite things. How can I fix this?
I am calling LuaLaTeX here on after calling biber 2.0.

The example code would look like the following. From the error message, it does not look like any other specifics (of the content, for instance) is related to the error.
% !BIB TS-program = biber
% !BIB program = biber
\documentclass[11pt,english]{article}
\usepackage[utf8]{inputenc}
\usepackage{fontspec}
\usepackage{polyglossia}
\setmainlanguage{english}
\usepackage[style=apa,backend=biber]{biblatex}
\addbibresource{myfile.bib}
\begin{document}
\textcite{label}
\printbibliography
\end{document}
biblatex? Can you please try with version2.9a(or whatever the latest wa) in an extra folder? – Johannes_B Apr 30 '15 at 15:55\usepackage[english]{babel}(or nothing) does not help, even though a comment from 2012 on the linked question saysBiblatex-apa now includes an english.lbx. Also, remember that biblatex doesn't really support polyglossia, only babel– László Apr 30 '15 at 16:13\DeclareLanguageMapping{british}{british-apa}The problem with other question was the missing language mapping. That is fixed by now. ut, you need to load one language mapping, which isn't the case above. – Johannes_B Apr 30 '15 at 16:14englishis not supposed to work? Even there is anenglish.lbx(which I could not verify, I cannot find the right folder in my installation)? Note I did not usebritishhere. – László Apr 30 '15 at 16:16\DeclareLanguageMapping{english}{english-apa}– Johannes_B Apr 30 '15 at 16:17