Biblatex: Bibliography for minimal Example doesn't appear in the PDF

Question

i want to use the solution provided in Biblatex: Adding time information to "online" field and a label in front of url I tried to launch the minimal example provided by Guido but the Bibliography isn't appearing in PDF file. I made a new Tex file and inserted this

\documentclass[a4paper, 
oneside, 
12pt, 
bibliography=totocnumbered, 
listof=totocnumbered
]{scrreprt}
\usepackage[english, ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage[babel,german=quotes]{csquotes}
\usepackage[automark]{scrpage2}
\usepackage[]{url}


\usepackage[backend=biber, style=authoryear, urldate=comp, dateabbrev=false]{biblatex}
\bibliography{source.bib}

\begin{filecontents}{biblatex-dm.cfg}
    \DeclareDatamodelFields[type=field,datatype=literal,skipout=false]{urltime}
\end{filecontents}
\DeclareFieldFormat{url}{\newline\bibstring[\MakeUppercase]{url}\addcolon\addspace\url{#1}}
\DeclareFieldFormat{urltime}{#1}
\DeclareFieldFormat{urldate}{%
  \iffieldundef{urlday}
    {}
    {\stripzeros{\thefield{urlday}}\adddot}%
  \iffieldundef{urlmonth}
    {}
    {\stripzeros{\thefield{urlmonth}}\adddot}%
  \printfield{urlyear}%
}

\renewbibmacro{url+urldate}{%
  \printfield{url}\setunit{\addcomma\addspace}
  \printurldate\addcomma\addspace
  \printfield{urltime}}

  \renewcommand{\newunitpunct}{\adddot}

  \renewcommand{\labelnamepunct}{\addcomma} 

  \AtEveryBibitem{\clearfield{month}} 




\begin{document}
Latex is science \parencite{stack}

\clearpage


\printbibliography

\end{document}

Then i made a source.bib file and entered this:

@online{stack,
    author = {Stack},
    title = {Why {\LaTeX} is science},
    month = {april},
    year = 2012,
    url = {www.tex.stackexchange.com},
    urldate = {2013-04-29}
} 

I use a portable TexMaker. What am i doing wrong? Thanks in advance

Edit: it appears when i delete the argument backend=biber the bibliography is visible. Maybe there is something wrong with my TexMaker.

Edit2: I make sure both my files (.tex and .bib) are saved, then compile PDFLaTeX BibTeX PDFLaTeX PDFLaTeX and show pdf

in options\Configure Texmaker there is for PDFLaTeX : "../miktex/miktex/bin/pdflatex.exe" -interaction=nonstopmode %.tex BibTeX : "../miktex/miktex/bin/bibtex.exe" %.aux

Compiler says process exited normally every time but there are some blue (minor i guess) errors like:

LaTeX Warning: File `biblatex-dm.cfg' already exists on the system.
LaTeX Warning: Citation 'stack' on page 1 undefined on input line 49.
[1
{C:/Users/as24707/Documents/latex_portable/latex_portable/miktex/pdftex/config/
pdftex.map}]
LaTeX Warning: Empty bibliography on input line 54.
(P:\fd\ProdDev\BE\Externe-User\Sawicki_Adam_as24707\Diplom\LaTex\test\Test1.aux
)
LaTeX Warning: There were undefined references.
Package biblatex Warning: Please (re)run Biber on the file:
(biblatex) Test1
(biblatex) and rerun LaTeX afterwards.
Package logreq Info: Writing requests to 'Test1.run.xml'.
)

Edit3: My TexMaker is version 1.9.9 wich is outdated. Im trying to set the 4.1 running. Im gonna check back later to let you know how it went. Thanks a lot for all the help so far:)

Edit4: Ok im still far from ready. I installed portable versions of Miktex and Texmaker. Entry at Bib(la)Tex : Biber % doesnt work so i klicked on the blue foldery button an browsed for Biber file. Now it looks like this "C:/Users/as24707/Documents/latex_portable/latex_portable/MikTex/miktex/bin/biber.exe" %

when i use f11 on my actual document i get notification that i should use biber (my file is not properly adjusted jet). On the MWE from the topic above i use f11 and get following log

Process started

Use of uninitialized value $llabel in concatenation (.) or string at Biber.pm line 1851.

Use of uninitialized value $llabel in concatenation (.) or string at Biber.pm line 1865. Use of uninitialized value $llabel in concatenation (.) or string at Biber.pm line 1880.

Use of uninitialized value $llabel in concatenation (.) or string at Biber.pm line 2689.

Use of uninitialized value $llabel in concatenation (.) or string at Biber.pm line 2820.

Use of uninitialized value $llabel in concatenation (.) or string at Biber.pm line 1887.

Use of uninitialized value in string eq at Biber/Output/bbl.pm line 477.

Use of uninitialized value in string eq at Biber/Output/bbl.pm line 477. Use of uninitialized value in string eq at Biber/SortLists.pm line 77. Use of uninitialized value $label in string eq at Biber/SortLists.pm line 77. Use of uninitialized value $listlabel in concatenation (.) or string at Biber/Output/bbl.pm line 491. Use of uninitialized value $listlabel in concatenation (.) or string at Biber/Output/bbl.pm line 493.

INFO - This is Biber 1.4 INFO - Logfile is 'Test1.blg' INFO - Reading 'Test1.bcf' WARN - Warning: Found biblatex control file version 1.7, expected version 2.2 INFO - Found 1 citekeys in bib section 0 INFO - Processing section 0 INFO - Looking for bibtex format file 'source.bib' for section 0 INFO - Decoding LaTeX character macros into UTF-8 INFO - Found BibTeX data source 'source.bib' WARN - Labelname candidate 'shortauthor' is not a name field - skipping WARN - Labelname candidate 'author' is not a name field - skipping WARN - Labelname candidate 'shorteditor' is not a name field - skipping WARN - Labelname candidate 'editor' is not a name field - skipping WARN - Labelname candidate 'translator' is not a name field - skipping INFO - Overriding locale 'English_United States.1252' default tailoring 'variable = shifted' with 'variable = non-ignorable' INFO - Sorting 'entry' list '' keys INFO - No sort tailoring available for locale 'English_United States.1252' INFO - Writing 'Test1.bbl' with encoding 'UTF-8' INFO - Output to Test1.bbl INFO - WARNINGS: 6

Process exited normally

The bibliography is still not there unfortunately:(