hello, I have interfaced SICK lms291 laser with ros. Now i have to proceed with SLAM using gmapping. but i couldnt create a map using mapsaver cmnd. and my rviz display shows nothing though i could get my .vcg file from rviz. thank you !

i am a student doing my UG(B.E in Robotics& Automation Engg). now im doing this SICK LIDAR project in my internship.