This is a configuration problem that the administrator of the service needs to fix. In short, the place where the job was executed did not have access to the database where the server is running.
If one job fails with this reason, it might have been a small hiccup and a rerun might fix it. If many jobs are failing with this reason, it is a larger problem.
This was due to a dependency problem in most prior Q&A at this forum. Example: Specify column to group by -- Join two datasets -- Fixed
Should your admins need help, the Galax admin chat is here: https://gitter.im/galaxyproject/admins.