LyX ⇒ biblatex.sty cannot be accessed by Lyx

[felixhelix]

Hi,
I have problems with biblatex.sty:
I have installed it using sudo apt-get install texlive-bibtex-extra, and I can see it is there when I type kpsewhich biblatex.sty:
/usr/share/texlive/texmf-dist/tex/latex/biblatex/biblatex.sty
However, I still get the error message:

The cite engine biblatex-natbib requires a package that is not available in your LaTeX installation, or a converter that you have not installed. LaTeX output may not be possible.
Missing prerequisites:
biblatex.sty

I'm using Lyx 2.3.3 with Ubuntu 18.04.3 LTS.

Any ideas? Maybe some access restrictions?
Your's
Felix

[scottkosty]

Did you do tools > reconfigure after you installed it?