This error generally means that Lsyncd encountered an issue while trying to start. Common causes may include:

  1. Configuration Problems: Check that your Lsyncd configuration file (/etc/lsyncd/lsyncd.conf.lua) is free of syntax errors or incorrect parameters.
  2. Insufficient Permissions: Ensure that Lsyncd has the necessary permissions to access the directories and files it is trying to sync.
  3. Network or SSH Issues: If Lsyncd is using SSH for synchronization, there might be a connection problem with the remote server or an authentication issue (e.g., the public key hasn’t been set up correctly).
  4. Missing Dependencies: Ensure that all necessary dependencies for running Lsyncd are installed.

Check the logs at /var/log/lsyncd/lsyncd.log for more specific error details.