I have been working with some robot simulations for some time but suddenly robot models stopped launching in gazebo stopped launching giving the error; [gazebo-2] process has died [pid 3466, exit code 255, cmd /home/evan/catkinws/src/gazeborospkgs/gazeboros/scripts/gzserver -e ode /home/evan/mybotws/src/mybotgazebo/worlds/mybot.world _name:=gazebo _log:=/home/evan/.ros/log/e37cbab0-b913-11e8-94e5-441ca85eaa37/gazebo-2.log]. log file: /home/evan/.ros/log/e37cbab0-b913-11e8-94e5-441ca85eaa37/gazebo-2*.log I am using gazebo 7.14 version Please help