TF shows error as soon as I launch RTAB.

[avainb]

This is the status of my TF before I launch RTAB Map. For this I have kept Odom as the Fixed Frame -



And this is the status of my TF after I launch RTAB MAP. For this I have kept Map as the Fixed Frame -



Why do I get this error? Also my ROS Graph after I launch RTAB is -

[matlabbe]

See https://github.com/introlab/rtabmap_ros/issues/1319