ERROR: Cross sections XML file does not exist!

Dear OpenMC Users Group

I recently installed openmc on ubuntu 16.04. When I try to run the sample tests, I get the error message: ERROR: Cross sections XML file
‘/home/lababsa/openmc/data/nndc/cross_sections.xml:’ does not exist! even I set the CROSS_SECTIONS environment variable
in .bashrc file

export CROSS_SECTIONS=$HOME/openmc/data/nndc/cross_sections.xml:$CROSS_SECTIONS

Screenshot from 2018-04-23 17-36-15.png