jezZiFeR wrote: > When I export from Lyx without using XeTex (removed the line in the > preamble), then Texshop shows some errors like "no author given" and > some more (I couldn´t copy them). Interestingly I here also get the > "undefined control sequence".
Before you try anything else, could you please tell us which versions of biblatex and biblatex-dw you are using? Maybe they are incompatible. And you said that biblatex was working before, so maybe the problem is not the installation. If you don't know the versions of the packages, you can add \listfiles to your preamble and see the versions of all packages at the end of the *.log file (which is produced when you try to compile the document and which is stored in a subdirectory of the LyX temp directory). Regards, Dominik.-