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Could not retrieve the system state of the ROS master - error

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I'm getting the error in the title when I'm trying to create a publisher or subscriber. The ROS master and the Matlab script run on the same machine.
Matlab can connect to the ROS master and the matlab node is visible when running 'rosnode list'.
rosMaster = "";
lidarTopic = "/os_cloud_node/points";
segmentedLidarTopic = "/segmentedImages";
sub = rossubscriber(lidarTopic);
pubLidar = rospublisher(segmentedLidarTopic, 'sensor_msgs/Image');
The error happens on both of the last 2 lines of code. I wasn't able to find any information on how to approach this error message.
If anyone can help it would be much appreciated!
Anthony Schenck
Anthony Schenck on 6 Dec 2020
1&2:The machine, an nVidia drive, is running Ubuntu indeed. The ROS master is started from the console. We initially tested the matlab script while a couple of different ros-nodes were running. When this failed we tested with just the rosmaster running from console ($roscore) which resulted in the same error.
3&4: Unsure at this moment, will check tomorrow.
(I initially tested the script at home, with a ROS master running ubuntu 18.04 and ros kinetic and the matlab script running on a linux mint 20.04 machine, and this worked without issues. )
*Edit: The machine in not an nVidia drive, it's a desktop pc with an i7 6700 processor running Ubuntu 18.04
3: ROS Kinetic
4: This works fine, the subscriber and the publisher get created without the error
I also tested with the rosbag we use on my home setup and this worked without any issues too.
Any other debugging strategies would be welcome!

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Accepted Answer

Anthony Schenck
Anthony Schenck on 14 Dec 2020
Apparently the issue was caused by a beta driver of Ouster, v1.14. We reverted to v1.12 and everything is working now.
  1 Comment
Mohan on 16 Feb 2021
Hello Anthony,
How does one revert to Ouster V1.12 from V1.14? I have never done something like that before so would appreciate some help. Thanks!

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