# Rviz error when launching navigation (ROS2, SE3) **URL:** \ **Category:** Ask\ **Created:** [July 18, 2024, 8:00pm UTC](https://forum.hello-robot.com/t/rviz-error-when-launching-navigation-ros2-se3/1044 "2024-07-18T20:00:12Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![Mohamed\_Fazil](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/mohamed_fazil/32/261_2.png) [@Mohamed\_Fazil](https://forum.hello-robot.com/u/Mohamed_Fazil)\ **Post date:** [July 22, 2024, 6:53pm UTC](https://forum.hello-robot.com/t/rviz-error-when-launching-navigation-ros2-se3/1044/4 "2024-07-22T18:53:31Z")
Hi @allen, I believe this issue got fixed with our recent [bug fix](https://github.com/hello-robot/stretch_ros2/commit/d8ce9660e3d922cbdfc6d18f3cb887ba2b38e2b2) to Stretch ROS2. It is related to a bug where importing `cv2` causes other QT applications to crash, which is Rviz, in your case, exits the demo. Have described it in his post > [@QT applications error out due to conflict with cv2 (Could not load the Qt platform plugin "xcb")](https://forum.hello-robot.com/t/qt-applications-error-out-due-to-conflict-with-cv2-could-not-load-the-qt-platform-plugin-xcb/1047): > > We would like to address an existing bug that will likely occur using Python scripts that import the cv2 library and have a component that uses the linux apt installed QT platform to run a GUI. The error output would look like the following: qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "/home/hello-robot/.local/lib/python3.10/site-packages/cv2/qt/plugins" even though it was found. This application failed to start because no Qt platform plugin could be initialized. Reinstalling … Could you pull the latest `stretch_ros2` repository updates, rebuild your workspace, and then try re-running the demo? --- _[View the full topic](https://forum.hello-robot.com/t/rviz-error-when-launching-navigation-ros2-se3/1044)._