The robot was not able to create a map of its environment. This can happen due to multiple reasons.
1. Replace the base station and make sure that there are no obstacles close to the station (50 cm to each side, 30 cm above). Make sure that there are no objects on the ground that could get the robot stuck (e.g. cables) or could be pushed around by the robot (e.g. shoes).
2. If creating the map should fail after several attempts, please try the Exploring/Discovery process in a smaller room. If this is successful, please try again in a bigger room.