Error: Failed during "Preparing files for S3 deployment"

I keep getting this error for every deployment we do. Can’t see any error from the export log. Here are some details that might help:

  • As mentioned, no error in the export log even if debugging is enabled
  • The only error I see with Chrome’s inspect network activity is a 504 error to https://xxx/wp/wp-admin/admin-ajax.php?_fs_blog_admin=true. We usually see one 504 error right before the deployment fails.
  • Crawl increment and Deployment batch size are both set to 1
  • max_execution_time is set to 0
  • We’ve been using the plugin for a couple of months now and mostly deployment succeeds. I’m not sure why it started failing.
  • Using wp2static 6.6.7
  • Successful deployments in the past usually took about 5 minutes.

What happens during this preparing files for deployment and what could be causing the error?