When launching test_velodyne.launch getting error: Input cloud doesn't have "t", "time", "stamps" or "timestamp" field!

[astef3]

ROS distro: Noetic Ubuntu 20.04

Hi, I tried to use the test_velodyne.launch file with Velodyne data from rosbag. But, when I launched the test_velodyne.launch file (unchanged) and played the velodyne rosbag, I get constant errors:

Input cloud doesn't have "t", "time", "stamps" or "timestamp" field! Failed to deskew input cloud, aborting odometry update!

Can you please help me with resolving this issue? Because I understand that the second error (deskew) is because of the first one, but I cannot understand how its possible that the input cloud is without timestamp, when Velodyne PointCloud2 messages always provide time as well.

Thank you in advance for your time and help.

[matlabbe]

Can you verify that your bag has really a timestamp channel? Otherwise, you can disable deskewing in that example.