pgfplot gives an error despite using the latest version v1.7 [closed]

Question

I keep getting this error every time I compile using the pgfplot package

"! Package pgfkeys Error: I do not know the key '/pgfplots/error bars/ .cd' and I am going to ignore it. Perhaps you misspelled it."

I am using the latest version of pgfplot v1.7

Can some one please help me

---

Firstly I am a complete novice to Latex. So I am not sure what a "MWE" is and setting up the problem is extremely challenging in itself. But I will try my best to pose the problem. Secondly, please note that the code given below is NOT at all complete and simply copy-pasting it might not work. I just want to show the bare necessities. Thirdly, if the experts require more information, let me know and I will do my best to fill in the blanks.

Code:

\documentclass[%
12pt,   
oneside,
]{report}
%Packages used
\usepackage{graphicx}
\usepackage{makeidx} 
\usepackage{amssymb, amsmath} 
\usepackage[]{hyperref}     
\usepackage[greek,english]{babel}
\usepackage[font=small,format=plain,labelfont=bf,up,textfont=it,up]{caption} % Figure captions
\usepackage[all=normal,floats,leading,paragraphs, charwidths,tracking,wordspacing]{savetrees} 
\setlength{\parskip}{\baselineskip} 
\usepackage{pgfplots} %Uses pgfplots packages to make plots inside LATEX environment

\begin{document}
\chapter{section}
\markright{section}
%==================================================================
\section{calculations}
%==================================================================
\begin{figure}
\centering
\begin{tikzpicture}
\begin{axis}[
xlabel = xxx
ylabel = yyy
]
\addplot [red, only marks, error bars/.cd, y dir=both,y explicit]
coordinates {
(1,1)+-(0,0.2)
(2,2)+-(0,0.2)
(3,3)+-(0,0.1)  
};
\end{axis}
\end{tikzpicture}
\end{figure}
\end{document}

---

Error:

"! Package pgfkeys Error: I do not know the key '/pgfplots/error bars/ .cd' and I am going to ignore it. Perhaps you misspelled it."

Solution:

Change error bars/.cd to error bars

Reason:

I think its because the program cannot find the correct directory path. But I am not sure so don't take my word on it.