Entire error message: “This job number has been used in the past for a different job in this branch. Job numbers cannot be reused within a branch, because doing so would make payroll history reports misleading. Please choose a new job number.”
This error means that you are trying to add a new job with a job number and payroll branch that both already exist on a different job. Even when a job has been closed, the history remains. You will need to choose a new number.