Comment 3 for bug 1597921

apparently the insertion of --export-area-drawing option to --export-plain-svg option crased --export-pdf option.

Strangelly 0.91 produced files are not affected.

This command does not work with 0.92 files:

inkscape filename.svg -i layer1 -j -C --export-pdf=layer1.pdf

So I had to firstly export to SVG and then to PDF

inkscape filename.svg -i layer1 -j -C --export-plain-svg=layer1.svg
inkscape layer1.svg --export-pdf=layer.pdf

By the way. I had to produce a Python file to read SVG as an XML file and export each layer to a page of a PDF file, exporting a multi-page PDF.
I would like to suggest that a native option to export multi-page PDF be added on the next releases.