I’m using realsense D435 camera and Ubuntu 16.04. I followed the installation guide closely and my camera turns on with realsense viewer on Linux. However I cannot run the trial also the activation box is greyed out. My environment variables are the same as the manual echo $NUITRACK_HOME= /usr/etc/nuitrack, LD_LIBRARY_PATH =/usr/local/lib/nuitrack. I don’t know what the problem is, please help!