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Lighthouse Troubleshooting Guide

Please follow below troubleshooting guide if you face any of the listed issues while running the lilghthouse.

  • A. JWT Token authorization Error
  • If below command returns “failed JWT authorization erro: Invalid Token”, then follow these steps to fix it.
sudo journalctl -f -u lighthousebeacon.service -o cat | ccze -A


  • Stop lighthousebeacon by running-
sudo systemctl stop lighthousebeacon


  • Now, start it again by running
sudo systemctl start lighthousebeacon


  • Again check with above journalctl command and the error should be fixed now. /img/aws/ethereum-fullnode/lighthouse-logs.png
  • B. Lighthouse Connection Refused Error
  • If you get Connection refused error after running the journalctl command as shown in the screenshot below then follow these steps- /img/aws/ethereum-fullnode/lighthouse-connection-refused-error.png
  • This error indicates that geth process is not running. Check the status of geth command by running
  ps -ef | grep geth

Note: If sync is in progress, you will see the below highlighted process running.


  • If sync process is not running, then restart it by running-

Note: Make sure below command is executed from terminal inside Remote desktop GUI to avoid process termination.

sudo nohup geth --http --http.addr "" --http.port "8545" --http.corsdomain "*" --config /home/ubuntu/ethereum/eth_config.toml >> /var/log/cloud-init-output.log 2>&1 &


  • Now check the sync process again by running-
  ps -ef | grep geth
  • This time journalctl command should return the sync status- /img/aws/ethereum-fullnode/lighthouse-logs.png

    • C. WARN CPU seems incompatible with optimized Lighthouse build
    • If you are getting “WARN CPU seems incompatible with optimized Lighthouse build” warning and “failed with result ‘core-dump’.” error message in the journal log , the restart the vm and it should fix the issue.
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