# Revision history [back]

### "Failed to read sensor package." warning and Turtlebot

I'm still trying to track down problems with being unable to run the Turtlebot odometer/gyro calibration. When I startup the Turtlebot with the following command:

roslaunch turtlebot_bringup minimal.launch


I'll start seeing the following warning occur every 30 seconds or so.

[WARN] [WallTime: 1360633793.535097] Failed to read sensor package. 5 retries left.


What is the source of this warning? Is this something to be concerned about? Or, can it be ignored?