LyX ⇒ Lyx/Biblatex/Biber does not print bibliography

[margret]

Dear All

I changed my Dissertation from bibtex to biblatex and biber - following the rules of the wiki (http://wiki.lyx.org/BibTeX/Biblatex#using-biber) exactly. In a small test document it worked.
However, in my dissertation with exactly the same changes the literature is just not added and the bibliography not printed
(though when working in the document i see it - when i generate a PDF no bibliography appears and in the text it is just Fat (--not existent?)

this is the part in my preamble
\usepackage[english]{babel}
\usepackage[style=authoryear,natbib=true]{biblatex}
\bibliography{"C:/Users/margret/Desktop/Dissertation/ibrary.bib"}
\typeout{File:\jobname.bcf}

i added \printbibliography in the end as TEXCode, the bibliography is in the beginning in a note
in Documents Setting I changed the processor to biber...
i changed the preamble with or without backend=biber
After a whole work day trying to figure it out I ran out of options - can you help me?

Thanks a lot in advance for any hint!

[Deve]

I think the \bibliography command expects the bib file without the suffix .bib. So according to http://wiki.lyx.org/BibTeX/Biblatex you should either use

\bibliography{C:/Users/margret/Desktop/Dissertation/ibrary}

or

\addbibresource{C:/Users/margret/Desktop/Dissertation/ibrary.bib}

Also, I'm not sure whether quotation marks should be used inside the \bibliography command.