The HTML publisher plugin causes problems when running concurrently with other instances of the same job. It looks like both running tasks attempt to update the front page link at the same time and cannot. Please see attached log file. I have edited some project specific names for the sake of confidentiality.
We are attempting several work arounds:
1. Keep past HTML reports to see if it changes the way the reports are linked
2. Link against last successful build to see if it imposes some kind of intelligent running process check.
If these fail we are going to try publishing reports from the parent job who initiates multiple downstream builds.