I have before the beginning of the document \addbibresource{references.bib} and at the end of it \printbibliography.
The references have this format :
@ARTICLE{2015MNRAS.452.1089P,
author = {{Porth}, O. and {Komissarov}, S.~S.},
title = "{Causality and stability of cosmic jets}",
journal = {\mnras},
archivePrefix = "arXiv",
eprint = {1408.3318},
primaryClass = "astro-ph.HE",
keywords = {instabilities, MHD, relativistic processes, stars: jets, galaxies: active, galaxies: jets},
year = 2015,
month = sep,
volume = 452,
pages = {1089-1104},
doi = {10.1093/mnras/stv1295},
adsurl = {http://adsabs.harvard.edu/abs/2015MNRAS.452.1089P},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
No error, but doesn't print a thing.
\documentclass[12pt,twoside]{report}
\usepackage[utf8]{inputenc}
\usepackage[english,greek]{babel}
\usepackage[a4paper,width=160mm,top=25mm,bottom=25mm,bindingoffset=6mm]
{geometry}
\usepackage{amsmath}
\usepackage{esint}
\usepackage[normalem]{ulem}
\usepackage{graphicx}
\usepackage{subcaption}
\graphicspath{{Images/}}
\usepackage{array}
\usepackage{wrapfig}
\usepackage{multirow}
\usepackage{tabu}
\usepackage{wrapfig}
\usepackage{hyperref}
\usepackage{fancyhdr}
\newcommand{\uvec}[1]{\boldsymbol{\hat{\textbf{#1}}}}
\pagestyle{fancy}
\fancyhead{}
\fancyhead[RO,LE]{Αλληλεπίδραση αστροφυσικών πιδάκων πλάσματος με το περιβάλλον
τους}
\fancyfoot{}
\fancyfoot[LE,RO]{\thepage}
\fancyfoot[LO,CE]{Κεφάλαιο \thechapter}
\renewcommand{\headrulewidth}{0.4pt}
\renewcommand{\footrulewidth}{0.4pt}
\usepackage[style=authoryear,sorting=none]{biblatex}
\addbibresource{references.bib}
\title{Αλληλεπίδραση πιδάκων με το περιβάλλον τους}
\date{Oκτώβριος 2017}
\begin{document}
"
End: "
\nocite{*}
\printbibliography
\end{document}

\autocite{2015MNRAS.452.1089P}somewhere. Or if you want to add everything in the.bibfile to the reference list without citing them,\nocite{*}. – Torbjørn T. Oct 26 '17 at 16:34\printbibliography. And of course, you need to runbiberas daleif mentioned above. – Torbjørn T. Oct 26 '17 at 16:40