# [yocto:/# roslaunch voxl_cam_ros tracking_slave.launch] Error Message ?

Source: https://forum.modalai.com/topic/1212/yocto-roslaunch-voxl_cam_ros-tracking_slave-launch-error-message
Category: Autonomy: VIO, Mapping and Navigation (https://forum.modalai.com/category/19/autonomy-vio-mapping-and-navigation)
Tags: apriltag
Posted: 2022-08-17 00:02:18 UTC by Hyosun Yoo
Replies: 0 · Views: 2566

## Hyosun Yoo · 2022-08-17 00:08:43 UTC

@Hyosun-Yoo said in [\[yocto:/\# roslaunch voxl\_cam\_ros tracking\_slave\.launch\] Error Message ?](/post/5636):
> Re: [AprilTag Relocalization](/topic/455/apriltag-relocalization)
> 
> Dear
> I got an error message when I run this command.
> 
> [yocto:/# roslaunch voxl_cam_ros tracking_slave.launch]
> 
> 
> Please tell me how to solve this message.
> 

> VOXL Vision (modalai-3-2-0-0.3.4-b.tar.gz)
> VOXL Vision PX4 Apriltag Relocalization error

> Error message
> ================
> ERROR: could not open camera subscriber for cam id 1
> [ERROR] [1034.046473200]: CameraManager::Initialize() failed
> [ERROR] [1034.046845023]: Unable to open camera.
> ===============*
>![5c2c6beb-9c8b-432b-8430-fcc4d81c1ef3-image.png](https://forum.modalai.com/assets/uploads/files/1660694916409-5c2c6beb-9c8b-432b-8430-fcc4d81c1ef3-image.png)  

> Thank you so much.
> Mr. Yoo, hyosun