If the file
is empty, Jenkins will still initialize but the job will "disappear" from the dashboard. This will be logged, but may go unnoticed.
Oct 27, 2011 3:10:24 PM jenkins.model.Jenkins$6 onTaskFailed
SEVERE: Failed Loading job accurev_trigger
hudson.util.IOException2: <path>/configuration/jobs/<job>/nextBuildNumber doesn't contain a number