I am using Polymake 2.13-1 on Debian Linux, and I downloaded Paffenholz' database of Fano polytopes in dimension 4 from http://polymake.org/polytopes/paffenholz/www/fano.html.
When I start Polymake and do the following
$c = load("F.4D.0000.poly"); # this file just contains a single fano polytope
Polymake replies (how can I switch that off, by the way?)
polymake: validating XML file /home/mws/fano/5d/F.4D.0000.poly
polymake: XML validation succeeded
Printing the number of vertices, etc. seems to work fine. Now, if I continue with
$d = conv($c, scalar($c, -1));
and then give out the number of vertices, Polymake suffers a segmentation fault.
I attached the file for convenience.