Create map with cartographer on Multibot scenario does not work

[Kadlu]

I’m in ROS2 Navigation (Galactic) 6 - Multirobot Navigation.
I tried to create a map according suggested steps. After launch the multi_cartographer i always get the following warning: [occupancy_grid_node-2] [WARN] [1699808994.960191879] [occupancy_grid_node]: submap_slices and last_frame_id is empty
And no map get’s created. I went back to chapter 2 and was able to create a map.
I checked everything twice but was not able to fix it. Unfortunately there is no mentioned solution in case of an error.
Any suggestions?

[albertoezquerro]

Hello @Kadlu,

I just tested this exercise and it’s working ok for me, so I’d guess you are probably missing some step from the exercise. Please review it again and make sure that you are setting all the frames correctly, and that you are remapping to the proper topics.

In any case, for this chapter this is not necessary, as the map you will create is the same as the map for chapter 2. So you can complete the unit using the map from chapter 2.