help with cartographer_ros error "Check failed: frame_id[0] != '/' ('/' vs. '/') The frame_id /os1_imu should not start with a /"

edit

I'm a ROS noob and im kinda at a loss with this one. i read through the http://wiki.ros.org/tf2/Migration but didnt understand what file to edit to remove the "/" from the frame id of /os1_imu. Any help or guidance would be great. Thanks

PARAMETERS
 * /rosdistro: melodic
 * /rosversion: 1.14.3
 * /use_sim_time: True

NODES
  /
    cartographer_occupancy_grid_node (cartographer_ros/cartographer_occupancy_grid_node)
    cartographer_offline_node (cartographer_ros/cartographer_offline_node)
    rviz (rviz/rviz)

auto-starting new master
process[master]: started with pid [1678]
ROS_MASTER_URI=http://localhost:11311

setting /run_id to 2eb3f036-0191-11ea-bdb7-0242ac110007
process[rosout-1]: started with pid [1689]
started core service [/rosout]
process[rviz-2]: started with pid [1696]
process[cartographer_offline_node-3]: started with pid [1697]
process[cartographer_occupancy_grid_node-4]: started with pid [1698]
[ INFO] [1573153366.108874864]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/root/catkin_ws/src/ouster_example/ouster_ros/../../ouster_example/cartographer_ros/configuration_files/cart_3d.lua' for 'cart_3d.lua'.
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
qt.qpa.screen: QXcbConnection: Could not connect to display :0
Could not connect to any X display.
[ INFO] [1573153366.110265334]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/opt/ros/melodic/share/cartographer/configuration_files/map_builder.lua' for 'map_builder.lua'.
[ INFO] [1573153366.110340718]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/opt/ros/melodic/share/cartographer/configuration_files/map_builder.lua' for 'map_builder.lua'.
[ INFO] [1573153366.110428682]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/opt/ros/melodic/share/cartographer/configuration_files/pose_graph.lua' for 'pose_graph.lua'.
[ INFO] [1573153366.110476645]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/opt/ros/melodic/share/cartographer/configuration_files/pose_graph.lua' for 'pose_graph.lua'.
[ INFO] [1573153366.110629318]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/opt/ros/melodic/share/cartographer/configuration_files/trajectory_builder.lua' for 'trajectory_builder.lua'.
[ INFO] [1573153366.110669058]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/opt/ros/melodic/share/cartographer/configuration_files/trajectory_builder.lua' for 'trajectory_builder.lua'.
[ INFO] [1573153366.110742121]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/opt/ros/melodic/share/cartographer/configuration_files/trajectory_builder_2d.lua' for 'trajectory_builder_2d.lua'.
[ INFO] [1573153366.110786759]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/opt/ros/melodic/share/cartographer/configuration_files/trajectory_builder_2d.lua' for 'trajectory_builder_2d.lua'.
[ INFO] [1573153366.110907515]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/opt/ros/melodic/share/cartographer/configuration_files/trajectory_builder_3d.lua' for 'trajectory_builder_3d.lua'.
[ INFO] [1573153366.110952316]: I1107 19:02:46.000000  1697 configuration_file_resolver.cc:41] Found '/opt/ros/melodic/share/cartographer/configuration_files/trajectory_builder_3d.lua' for 'trajectory_builder_3d.lua'.
[ INFO] [1573153366.135847595]: I1107 19:02:46.000000  1697 playable_bag.cc:63] Processed 0.0497542 of 11.3957 seconds of bag /home/data/scan6.bag
[ INFO] [1573153366.136909731]: I1107 19:02:46.000000  1697 submap_3d.cc:321] Added submap 1
[ INFO] [1573153366.136950152]: I1107 19:02:46.000000  1697 map_builder_bridge.cc:130] Added trajectory with ID '0'.
[ INFO] [1573153366.136975965]: I1107 19:02:46.000000  1697 offline_node.cc:270] Assigned trajectory 0 to bag /home/data/scan6.bag
F1107 19:02:46.137030  1697 sensor_bridge.cc:33] Check failed: frame_id[0] != '/' ('/' vs. '/') The frame_id /os1_imu should not ...