Troubleshooting

1. X11 error when running object detection notebooks on EC2 instances.

When you run object detection notebooks on EC2 instances via SSH, sometimes you may face X11 error when drawing bounding boxes.

java.awt.HeadlessException:
No X11 DISPLAY variable was set, but this program performed an operation which requires it.
java.awt.HeadlessException:

Here is how you can solve it:

• Use -X to ssh to your EC2 instance.

ssh -X -i "your_pem_file.pem" user-name@ip.address -L local-port-number:localhost:8888

follow this guide for how to run notebook on EC2 instances in general.

• Install Xvfb package on your EC2 instance:

sudo apt-get install -y xvfb

• Run the following command to on a tmux session:

Xvfb :1

• Set DISPLAY variable to the same value where Xvfb is running.

export DISPLAY=:1

• Now start jupyter notebook normally and run the notebook

jupyter notebook

Reference