Natbib citation issue

Question

I cannot seem to get natbib to work with author-year style citations.

The following standalone example:

\documentclass{article} 

\usepackage[authoryear]{natbib}

\usepackage{filecontents}

\begin{filecontents}{\jobname.bib}

@misc{A01,
   author = {Test, A. and Foo, B.},
   year = {2001},
   title = {Alpha},
}

@misc{A02,
   author = {Alex, A. and Bar, B.},
   year = {2005},
   title = {Alpha},
}

\end{filecontents}

\begin{document}

\citep{A01}, \citep{A02}, \citet{A02} 

\bibliography{\jobname}


\end{document}

Simply returns the error

"! Package natbib Error: Bibliography not compatible with author-year itations."

I have looked about at the various answers surrounding this error but can't work out what's wrong in my case.

Thanks for any help :)

EDIT: Have added screenshot of code with the log-file too below:

Answer 1

Well, there seem to be two problems:

1. You missed to add a bibliographystyle like \bibliographystyle{abbrvnat}
2. It seems your TeX distribution is a little bit outdated ...

With the following MWE

\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}
@misc{A01,
  author = {Test, A. and Foo, B.},
  year = {2001},
  title = {Alpha},
}
@misc{A02,
  author = {Alex, A. and Bar, B.},
  year = {2005},
  title = {Alpha},
}
\end{filecontents}


\listfiles %<========= creates list of used packages and version numbers
\documentclass{article} 

\usepackage[authoryear]{natbib}


\begin{document}

\citep{A01}, citep: \citep{A02}, citet: \citet{A02} 

\bibliographystyle{abbrvnat} % <=======================================
\bibliography{\jobname}

\end{document}

I get without error message the following result:

If you take a look into the .log file (for example 386491.log, if the TeX file is names 386491.tex)

This is pdfTeX, Version 3.14159265-2.6-1.40.18 (MiKTeX 2.9.6400 64-bit) (preloaded format=pdflatex 2017.4.26)  15 AUG 2017 19:37
entering extended mode
**./386491.tex
(386491.tex
LaTeX2e <2017-04-15>
Babel <3.9r> and hyphenation patterns for 76 language(s) loaded.
("C:\Program Files\MiKTeX 2.9\tex\latex\filecontents\filecontents.sty"
Package: filecontents 2011/10/08 v1.3 Create an external file from within a LaTeX document
)

LaTeX Warning: Overwriting file `./386491.bib'.

\openout15 = `386491.bib'.


("C:\Program Files\MiKTeX 2.9\tex\latex\base\article.cls"
Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
("C:\Program Files\MiKTeX 2.9\tex\latex\base\size10.clo"
File: size10.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
)
\c@part=\count79
\c@section=\count80
\c@subsection=\count81
\c@subsubsection=\count82
\c@paragraph=\count83
\c@subparagraph=\count84
\c@figure=\count85
\c@table=\count86
\abovecaptionskip=\skip41
\belowcaptionskip=\skip42
\bibindent=\dimen102
) ("C:\Program Files\MiKTeX 2.9\tex\latex\natbib\natbib.sty"
Package: natbib 2010/09/13 8.31b (PWD, AO)
\bibhang=\skip43
\bibsep=\skip44
LaTeX Info: Redefining \cite on input line 694.
\c@NAT@ctr=\count87
)
(386491.aux)
\openout1 = `386491.aux'.

LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 23.
LaTeX Font Info:    ... okay on input line 23.
LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 23.
LaTeX Font Info:    ... okay on input line 23.
LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 23.
LaTeX Font Info:    ... okay on input line 23.
LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 23.
LaTeX Font Info:    ... okay on input line 23.
LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 23.
LaTeX Font Info:    ... okay on input line 23.
LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 23.
LaTeX Font Info:    ... okay on input line 23.
 (386491.bbl) [1

{C:/Users/Internet/AppData/Local/MiKTeX/2.9/pdftex/config/pdftex.map}] (386491.aux)

 *File List*
filecontents.sty    2011/10/08 v1.3 Create an external file from within a LaTeX document
 article.cls    2014/09/29 v1.4h Standard LaTeX document class
  size10.clo    2014/09/29 v1.4h Standard LaTeX file (size option)
  natbib.sty    2010/09/13 8.31b (PWD, AO)
  386491.bbl
 ***********

 ) 
Here is how much of TeX's memory you used:
 564 strings out of 493324
 6475 string characters out of 3138984
 58170 words of memory out of 3000000
 4171 multiletter control sequences out of 15000+200000
 4245 words of font info for 16 fonts, out of 3000000 for 9000
 1141 hyphenation exceptions out of 8191
 24i,4n,32p,145b,312s stack positions out of 5000i,500n,10000p,200000b,50000s
<C:/Program Files/MiKTeX 2.9/fonts/type1/public/amsfonts/cm/cmbx12.pfb><C:/Program Files/MiKTeX 2.9/fonts/type1/public
/amsfonts/cm/cmr10.pfb>
Output written on 386491.pdf (1 page, 24658 bytes).
PDF statistics:
 14 PDF objects out of 1000 (max. 8388607)
 0 named destinations out of 1000 (max. 500000)
 1 words of extra memory for PDF output out of 10000 (max. 10000000)

you can see in the first line that I am using a current MiKTeX 2,9, version 3.14159265-2.6-1.40.18 (MiKTeX 2.9.6400 64-bit) and my system used the following packages (created with command \listfiles):

 *File List*
filecontents.sty    2011/10/08 v1.3 Create an external file from within a LaTeX document
 article.cls    2014/09/29 v1.4h Standard LaTeX document class
  size10.clo    2014/09/29 v1.4h Standard LaTeX file (size option)
  natbib.sty    2010/09/13 8.31b (PWD, AO)

Please compare this numbers with yours. From the screenshot you showed us I guess your sytem is a little bit older. Please update ...