Office 365: PST Import “Invalid Workload specified” error

This error can occure when the csv file being used for the PST import is incorrectly formatted.
To resovle this:

  1. Copy blank cells to any lines that may have been affected by previous editing (for example if data was deleted from cells previously in excel there may be spaces left that are invisible).
  2. Type in data manually without copy and pasting it.